U.S. patent application number 10/216470 was filed with the patent office on 2003-06-12 for bulk synthesis of carbon nanotubes from metallic and ethynyl compounds.
Invention is credited to Keller, Teddy M., Qadri, Syed B..
Application Number | 20030108477 10/216470 |
Document ID | / |
Family ID | 31187915 |
Filed Date | 2003-06-12 |
United States Patent
Application |
20030108477 |
Kind Code |
A1 |
Keller, Teddy M. ; et
al. |
June 12, 2003 |
Bulk synthesis of carbon nanotubes from metallic and ethynyl
compounds
Abstract
A process of making carbon nanotubes comprising the steps of:
providing a precursor composition comprising at least one metallic
compound and at least one organic compound; wherein the organic
compound is selected from the group consisting of an ethynyl
compound, a metal-ethynyl complex, and combinations thereof;
wherein the precursor composition is a liquid or solid at room
temperature; and heating the precursor composition under conditions
effective to produce carbon nanotubes. A carbon nanotube
composition comprising carbon nanotubes and a metal component
selected from the group consisting of metal nanoparticles and
elemental metal; wherein the carbon nanotube composition is
rigid.
Inventors: |
Keller, Teddy M.; (Fairfax
Station, VA) ; Qadri, Syed B.; (Fairfax Station,
VA) |
Correspondence
Address: |
Code 1008.2, Naval Research Laboratory
4555 Overlook Ave., S.W.
Washington
DC
20375-5320
US
|
Family ID: |
31187915 |
Appl. No.: |
10/216470 |
Filed: |
July 26, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10216470 |
Jul 26, 2002 |
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10006226 |
Dec 10, 2001 |
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10216470 |
Jul 26, 2002 |
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10006385 |
Dec 10, 2001 |
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Current U.S.
Class: |
423/447.1 |
Current CPC
Class: |
B82Y 30/00 20130101;
D01F 9/1273 20130101; Y10S 977/842 20130101; C01B 32/162 20170801;
B82Y 40/00 20130101; D01F 9/127 20130101; C01B 32/166 20170801 |
Class at
Publication: |
423/447.1 |
International
Class: |
D01F 009/12 |
Claims
We claim:
1. A process of making carbon nanotubes comprising the steps of:
providing a precursor composition comprising at least one metallic
compound and at least one organic compound; wherein the organic
compound is selected from the group consisting of an ethynyl
compound, a metal-ethynyl complex, and combinations thereof;
wherein the precursor composition is a liquid or solid at room
temperature; and heating the precursor composition under conditions
effective to produce carbon nanotubes.
2. The process of claim 1, wherein the metallic compound and the
organic compound are the same compound.
3. The process of claim 1, wherein the metal in the metallic
compound is selected from the group consisting of a transition
metal, iron, cobalt, nickel, ruthenium, osmium, molybdenum,
tungsten, yttrium, lutetium, boron, copper, manganese, silicon,
chromium, zinc, palladium, silver, platinum, tin, tellurium,
bismuth, germanium, antimony, aluminum, indium, sulfur, selenium,
cadmium, gadolinium, hafnium, magnesium, titanium, lanthanum,
cerium, praseodymium, neodymium, terbium, dysprosium, holmium,
erbium, and combinations thereof.
4. The process of claim 1, wherein more than one metal is present
in the precursor composition.
5. The process of claim 1, wherein the metallic compound is
selected from the group consisting of a metallocenyl compound, a
metal salt, a metal-ethynyl complex, and combinations thereof.
6. The process of claim 5, wherein the metallocenyl compound is
selected from the group consisting of a ferrocenyl compound, a
metallocenylethynyl compound, 1,4-bis(ferrocenyl)butadiyne,
metallocenylethynylaromatic compound,
1,3-bis(ferrocenylethynyl)benzene, 1,4-bis(ferrocenylethynyl)be-
nzene, 1-(ferrocenylethynyl)-3-(phenylethynyl)benzene,
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene,
1,3,5-tris(ferrocenylethy- nyl)benzene, a metallocenylethynyl
phosphine metal salt,
bis(ferrocenylethynyl)-bis(triphenylphosphine)nickel,
bis(ferrocenylethynyl)-bis(triethylphosphine)palladium,
bis(ferrocenylethynyl)-bis(triethylphosphine)platinum, and
combinations thereof.
7. The process of claim 5, wherein the metal salt is selected from
the group consisting of a metal carbonyl salt, nonacarbonyl diiron,
octacarbonyl dicobalt, dodecacarbonyl triruthenium, hexacarbonyl
tungsten, a phosphine metal salt, bis(triphenylphosphine)nickel,
bis(triethylphosphine)palladium, bis(triethylphosphine)platinum,
dicarbonyl bis(triphenylphosphine)nickel, palladium (II)
acetylacetonate, manganese (III)-2,4-pentanedionate,
cyclopentadienyl tungsten tricarbonyl dimer, and combinations
thereof.
8. The process of claim 1, wherein the metal-ethynyl complex is
selected from the group consisting of a metal carbonyl-ethynyl
complex, hexacarbonyl dicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene, hexacarbonyl diiron complex
of 1,2,4,5-tetrakis(phenylethynyl)benzene, nonacarbonyl
triruthenium complex of 1,2,4,5-tetrakis(phenylethynyl)benze- ne, a
metal carbonyl-metallocenylethynyl containing complex, hexacarbonyl
dicobalt complex of 1,4-bis(ferrocenyl)butadiyne, hexacarbonyl
dicobalt complex of l-(ferrocenylethynyl)-4-(phenylethynyl)benzene,
hexacarbonyl dicobalt complex of
1-(ferrocenylethynyl)-3-(phenylethynyl)benzene, and combinations
thereof.
9. The process of claim 1, wherein the ethynyl compound is selected
from the group consisting of an ethynylaromatic compound,
1,2,3-tris(phenylethynyl)benzene, 1,2,4-tris(phenylethynyl)benzene,
1,3,5-tris(phenylethynyl)benzene,
1,2,3,4-tetrakis(phenylethynyl)benzene,
1,2,3,5-tetrakis(phenylethynyl)benzene,
1,2,4,5-tetrakis(phenylethynyl)be- nzene,
1,2,3,4,5-pentakis(phenylethynyl)benzene,
1,2,3,4,5,6-hexakis(pheny- lethynyl)benzene, and combinations
thereof.
10. The process of claim 1, wherein at least one of the compounds
is an aromatic compound.
11. The process of claim 1, wherein the metal content of the
precursor composition is less than about 1% by weight.
12. The process of claim 1, wherein the heating step comprises
heating the precursor composition under nitrogen to a temperature
of at least about 500.degree. C.
13. The product made by the process of claim 1.
14. The process of claim 1, wherein the compounds are combined by a
method selected from the group consisting of mechanical mixing,
solvent mixing, and partial complexation.
15. A process of making carbon nanotubes comprising the steps of:
providing a precursor composition comprising a polymer and a
metallic component; wherein the polymer has crosslinked ethynyl
groups; wherein the metallic component is bonded to the polymer,
combined with the polymer, or combinations thereof; and heating the
precursor composition under conditions effective to produce carbon
nanotubes.
16. The process of claim 15, wherein the metallic component is
selected from the group consisting of a metallocenyl group, a
metal-ethynyl complex group, a metal salt, metal nanoparticles,
elemental metal, and combinations thereof
17. The process of claim 16, wherein the metallocenyl group is
ferrocenyl.
18. The process of claim 16, wherein the metal-ethynyl complex
group is selected from the group consisting of hexacarbonyl
dicobalt-ethynyl complex group, hexacarbonyl diiron-ethynyl complex
group, nonacarbonyl triruthenium-ethynyl complex group, and
combinations thereof.
19. The process of claim 16, wherein the metal salt is selected
from the group consisting of a metal carbonyl salt, nonacarbonyl
diiron, octacarbonyl dicobalt, dodecacarbonyl triruthenium,
hexacarbonyl tungsten, a phosphine metal salt,
bis(triphenylphosphine)nickel, bis(triethylphosphine)palladium,
bis(triethylphosphine)platinum, dicarbonyl
bis(triphenylphosphine)nickel, palladium (II) acetylacetonate,
manganese (III)-2,4-pentanedionate, cyclopentadienyl tungsten
tricarbonyl dimer, and combinations thereof.
20. The process of claim 15, wherein the heating step comprises
heating the precursor composition under nitrogen to a temperature
of at least about 500.degree. C.
21. The product made by the process of claim 15.
22. A carbon nanotube composition comprising carbon nanotubes and a
metal component selected from the group consisting of metal
nanoparticles, elemental metal, and combinations thereof; wherein
the carbon nanotube composition is rigid.
23. The carbon nanotube composition of claim 22, wherein the carbon
nanotube composition is made by a process comprising the steps of:
providing a precursor composition comprising at least one metallic
compound and at least one organic compound; wherein the organic
compound is selected from the group consisting of an ethynyl
compound, a metal-ethynyl complex, and combinations thereof;
wherein the precursor composition is a liquid or solid at room
temperature; and heating the precursor composition under conditions
effective to produce carbon nanotubes.
24. The carbon nanotube composition of claim 23, wherein the
metallic compound is selected from the group consisting of a
metallocenyl compound, a metal salt, a metal-ethynyl complex, and
combinations thereof.
25. The carbon nanotube composition of claim 22, wherein the carbon
nanotube composition is made by a process comprising the steps of:
providing a precursor composition comprising a polymer and a
metallic component; wherein the polymer has crosslinked ethynyl
groups; wherein the metallic component is bonded to the polymer,
combined with the polymer, or both; and heating the precursor
composition under conditions effective to produce carbon
nanotubes.
26. The carbon nanotube composition of claim 25, wherein the
metallic component is selected from the group consisting of a
metallocenyl group, a metal-ethynyl complex group, a metal salt,
metal nanoparticles, elemental metal, and combinations thereof.
27. The carbon nanotube composition of claim 22, wherein the metal
content of the carbon nanotube composition is less than about
1%.
28. The carbon nanotube composition of claim 22 further comprising
carbon nanoparticles.
29. A magnetic semiconductor comprising the carbon nanotube
composition of claim 22.
30. A superconductor comprising the carbon nanotube composition of
claim 22.
31. A fiber comprising the carbon nanotube composition of claim
22.
32. A shaped article comprising the carbon nanotube composition of
claim 22.
33. A powder made by grinding the carbon nanotube composition of
claim 22.
34. A film comprising the carbon nanotube composition of claim
22.
35. The film of claim 34, wherein the film comprises a plurality of
layers containing different concentrations of carbon nanotubes.
36. A composite comprising the carbon nanotube composition of claim
22.
37. A drug delivery system comprising the carbon nanotube
composition of claim 22.
38. A lubricant comprising the carbon nanotube composition of claim
22.
39. A microelectronic device comprising the carbon nanotube
composition of claim 22.
40. An electrode comprising the carbon nanotube composition of
claim 22.
41. A fuel cell electrode comprising the carbon nanotube
composition of claim 22.
42. A ferrofluid comprising the carbon nanotube composition of
claim 22, wherein carbon nanotube composition is ground to a
powder.
43. A battery comprising the electrode of claim 22.
44. A magnetic component comprising the carbon nanotube composition
of claim 22.
45. An electrical component comprising the carbon nanotube
composition of claim 22.
46. The electrical component of claim 45, wherein the electrical
component is a fiber.
47. A sensor comprising the carbon nanotube composition of claim
22.
48. A photovoltaic device comprising the carbon nanotube
composition of claim 22.
Description
[0001] This nonprovisional patent application is a
continuation-in-part application of U.S. patent application Ser.
No. 10/006,226 filed on Dec. 10, 2001 and a continuation-in-part
application of U.S. patent application Ser. No. 10/006,385 also
filed on Dec. 10, 2001. The U.S. patent application to Keller and
Qadri designated Navy Case 83,778 and titled "Synthesis of Metal
Nanoparticle Compositions from Metallic and Ethynyl Compounds,"
filed on the same day as the present application is incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to rigid carbon compositions
comprising carbon nanotubes and methods of synthesizing carbon
nanotubes in situ in a bulk material.
[0004] 2. Description of the Prior Art
[0005] There are a number of known methods for synthesis of carbon
nanotubes. Several are summarized in Journet et al., "Production of
carbon nanotubes," Appl. Phys. A 67, 1-9 (1998). These methods
include electric arc discharge, laser ablation, solar energy,
catalytic decomposition of hydrocarbons, electrolysis, synthesis
from bulk polymer of citric acid and ethylene glycol,
low-temperature solid pyrolysis of silicon carbonitride, and in
situ catalysis. These methods produce materials containing carbon
nanotubes in the form of powder, soot, soft material, hard shell,
rubbery material, filaments, porous material, and coatings. None of
these methods produces a rigid material containing carbon nanotubes
and metal.
[0006] Rinzler et al., "Large-scale purification of single-wall
carbon nanotubes: process, product, and characterization," Appl.
Phys. A 67, 29-37 (1998) discloses a method of making "bucky
paper." Bucky paper is a sheet that is made almost entirely of
carbon nanotubes. The method involves purifying single-walled
nanotubes (SWNT's) made by laser ablation. The SWNT's are dispersed
in aqueous solution and filtered. The filter cake is a bucky
paper.
[0007] Du et al., "Preparation of carbon nanotubes composite sheet
using electrophoretic deposition process," J. Mat. Sci. Lett. 21,
2002, 565-568 discloses a process of making a carbon nanotube/epoxy
composite. Carbon nanotubes were dispersed in a solution of EPI-Rez
and EPI-CURE in ethanol. Electrophoresis was used to deposit the
carbon nanotubes on an electrode. Evaporating the solvent produced
a carbon nanotube composite sheet containing about 55% carbon
nanotubes, but containing no metal.
[0008] There is need for rigid carbon composition containing carbon
nanotubes made by bulk synthesis.
SUMMARY OF THE INVENTION
[0009] It is an object of the invention to provide a process for
synthesizing carbon nanotubes in bulk.
[0010] It is a further object of the invention to provide rigid
carbon nanotube compositions.
[0011] It is a further object of the invention to provide carbon
nanotube materials that may be useful for structural, data storage,
microelectronic, motor, generator, battery, energy storage, sensor,
medical, and catalytic applications.
[0012] These and other objects of the invention may be accomplished
by a process of making carbon nanotubes comprising the steps of:
providing a precursor composition comprising at least one metallic
compound and at least one organic compound; wherein the organic
compound is selected from the group consisting of an ethynyl
compound, a metal-ethynyl complex, and combinations thereof;
wherein the precursor composition is a liquid or solid at room
temperature; and heating the precursor composition under conditions
effective to produce carbon nanotubes.
[0013] The invention further comprises a process of making carbon
nanotubes comprising the steps of: providing a precursor
composition comprising a polymer and a metallic component; wherein
the polymer has crosslinked ethynyl groups; wherein the metallic
component is bonded to the polymer, combined with the polymer, or
both; and heating the precursor composition under conditions
effective to produce carbon nanotubes.
[0014] The invention further comprises a carbon nanotube
composition comprising carbon nanotubes and a metal component
selected from the group consisting of metal nanoparticles and
elemental metal; wherein the carbon nanotube composition is
rigid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1(a) illustrates the Raman spectrum of the carbon
nanotube composition made in Example 94. FIG. 1(b) illustrates a
Raman spectrum of carbon nanotubes synthesized by a prior art
method.
[0016] FIG. 2 illustrates the Raman spectrum of the carbon nanotube
compositions made in Examples 80, 85, and 96.
[0017] FIG. 3 compares the x-ray diffraction pattern of the carbon
nanotube composition made in Example 91 to that of prior art carbon
nanofilaments and SWNT's.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The invention can allow for the synthesis of carbon
nanotubes in bulk material. Depending on the starting materials
used, the process can result in a rigid material. This may be
caused by melting of the starting materials to create a continuous
material in which the carbon nanotubes are made. The carbon
nanotubes may be SWNT's, multi-walled nanotubes (MWNT's), or
both.
[0019] The process of the invention comprises two steps: providing
a precursor composition and heating the precursor composition. In
the step of providing a precursor composition, the precursor
composition comprises at least one metallic compound and at least
one organic compound. In the heating step, the precursor
composition is heated under conditions effective to produce carbon
nanotubes.
[0020] Providing Step
[0021] The precursor composition comprises one or more compounds,
some or all of which are metallic compounds and some or all of
which are organic compounds. The precursor composition may comprise
a single compound that is both a metallic compound and an organic
compound. Either the metallic compound, the organic compound, or
both can be an aromatic compound. The precursor composition is a
liquid or solid at room temperature. It should be understood that
any reference to a compound can refer to one compound or to a
combination of different compounds. The same is also true for any
functional group, element, or component.
[0022] Any concentrations of the compounds that result in the
formation of carbon nanotubes can be used. Very small amounts of
metal may still result in carbon nanotubes. As the organic compound
may be the source of carbon for formation of carbon nanotubes, the
less organic compound used, the lower the yield of carbon nanotubes
may be. Organic compounds having a high percentage of inorganic
groups, such as silyl and siloxyl, may form few or no carbon
nanotubes due to their low carbon content. Such precursor
compositions may have a carbon nanotube yield of less than about
5%.
[0023] The metallic compound contains at least one metal atom. The
metal can be, but is not limited to, any metal that is known to
lead to the formation of carbon nanotubes by any previously known
method. Suitable metals can include, but are not limited to,
transition metals, iron, cobalt, nickel, ruthenium, osmium,
molybdenum, tungsten, yttrium, lutetium, boron, copper, manganese,
silicon, chromium, zinc, palladium, silver, platinum, tin,
tellurium, bismuth, germanium, antimony, aluminum, indium, sulfur,
selenium, cadmium, gadolinium, hafnium, magnesium, titanium,
lanthanum, cerium, praseodymium, neodymium, terbium, dysprosium,
holmium, erbium and combinations thereof. Although boron, sulfur,
and silicon are not traditionally referred to as metals, the term
"metal" as referred to herein includes these elements.
[0024] The metallic compound can be selected from, but is not
limited to, the group consisting of a metallocenyl compound, a
metal salt, a metal-ethynyl complex, and combinations thereof. More
than one of these types of compounds can be present, whether in the
same compound or in a combination of multiple compounds. For
example, hexacarbonyl dicobalt complex of
1,4-bis(ferrocenyl)butadiyne can be used as a metallic compound
having both a metallocenyl group and a metal-ethynyl complex.
Hexacarbonyl dicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene is an example of a
combination of a metal-ethynyl complex and a metallocenyl
compound.
[0025] Suitable metallocene compounds include, but are not limited
to, a ferrocenyl compound, a metallocenylethynyl compound,
1,4-bis(ferrocenyl)butadiyne, a metallocenylethynylaromatic
compound, 1,3-bis(ferrocenylethynyl)benzene,
1,4-bis(ferrocenylethynyl)benzene,
1-(ferrocenylethynyl)-3-(phenylethynyl)benzene,
1-(ferrocenylethynyl)-4-(- phenylethynyl)benzene,
1,3,5-tris(ferrocenylethynyl)benzene, a metallocenylethynyl
phosphine metal salt, bis(ferrocenylethynyl)-bis(trip-
henylphosphine)nickel,
bis(ferrocenylethynyl)-bis(triethylphosphine)pallad- ium,
bis(ferrocenylethynyl)-bis(triethylphosphine)platinum, and
combinations thereof. Examples 1-6 illustrate the synthesis of
certain metallocenyl compounds.
[0026] The metal-ethynyl complex can be the metallic compound, the
organic compound, or both. As used herein, the term "ethynyl"
includes both ethynyl groups and ethynylene groups. The term
"metal-ethynyl complex group" refers to only that part of a
metal-ethynyl complex containing the ethynyl group and the metal
group. Suitable metal-ethynyl complexes include, but are not
limited to, a metal carbonyl-ethynyl complex, hexacarbonyl dicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene, hexacarbonyl
diiron complex of 1,2,4,5-tetrakis(phenylethynyl)benzene,
nonacarbonyl triruthenium complex of
1,2,4,5-tetrakis(phenylethynyl)benze- ne, a metal
carbonyl-metallocenylethynyl complex, hexacarbonyl dicobalt complex
of 1,4-bis(ferrocenyl)butadiyne, hexacarbonyl dicobalt complex of
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene, hexacarbonyl
dicobalt complex of 1-(ferrocenylethynyl)-3-(phenylethynyl)benzene,
and combinations thereof. Examples 7-19 illustrate the synthesis of
certain metal-ethynyl complexes.
[0027] The metal-ethynyl complex can be a mixture of compounds,
even when referred to in singular form. This can be the case when
the metal-ethynyl complex is synthesized from a compound having
more than one ethynyl group. For example, 1:10 hexacarbonyl
dicobalt complex of 1,4-bis(ferrocenyl)butadiyne refers to a
combination of compounds containing about one mole of metal-ethynyl
complex groups for every ten moles of reacted and unreacted
1,4-bis(ferrocenyl)butadiyne. The descriptor "1:10" is the molar
ratio of the complex. The combination can include
1,4-bis(ferrocenyl)butadiyne with two metal-ethynyl complex groups,
1,4-bis(ferrocenyl)butadiyne with one metal-ethynyl complex group,
and unreacted 1,4-bis(ferrocenyl)butadiyne. The metal-ethynyl
complex can also be a single compound. An example of this is 2:1
hexacarbonyl dicobalt complex of 1,4-bis(ferrocenyl)butadiyne,
where every ethynyl group is in a metal-ethynyl complex group. Any
recitation of a metal-ethynyl complex that omits the molar ratio
refers to all molar ratios of the complex.
[0028] Suitable metal salts include, but are not limited to, a
metal carbonyl salt, nonacarbonyl diiron, octacarbonyl dicobalt,
dodecacarbonyl triruthenium, hexacarbonyl tungsten, a phosphine
metal salt, bis(triphenylphosphine)nickel,
bis(triethylphosphine)palladium, bis(triethylphosphine)platinum,
dicarbonyl bis(triphenylphosphine)nickel, palladium (II)
acetylacetonate, manganese (III)-2,4-pentanedionate,
cyclopentadienyl tungsten tricarbonyl dimer, and combinations
thereof.
[0029] Only a small amount of metal may be needed to form carbon
nanotubes. The metal content of the precursor composition may be
below about 1% by weight. Higher amounts may also be used. The
choice of metallic compound can influence the yield and nature of
the carbon nanotubes. The choice of metal can also influence the
electromagnetic properties and other properties of the carbon
nanotube composition.
[0030] The organic compound is selected from the group consisting
of an ethynyl compound, a metal-ethynyl complex, and combinations
thereof. The term "organic compound" refers to an organic compound
that is substantially free of silicon. The ethynyl compound is an
organic compound having one or more ethynyl groups. The ethynyl
compound can also be the same compound as the metal-ethynyl
complex. The metal-ethynyl complex is described above. This can
occur when the organic compound contains both one or more ethynyl
groups and one more metal-ethynyl complex groups. 1:1 Hexacarbonyl
diiron complex of 1,2,4,5-tetrakis(phenylethynyl)benzene is an
example of such a compound. The organic compound can also be a
monomer or a linear polymer containing an ethynyl group and/or a
metal-ethynyl complex group.
[0031] Suitable ethynyl compounds include, but are not limited to,
an ethynylaromatic compound, 1,2,3-tris(phenylethynyl)benzene,
1,2,4-tris(phenylethynyl)benzene, 1,3,5-tris(phenylethynyl)benzene,
1,2,3,4-tetrakis(phenylethynyl)benzene,
1,2,3,5-tetrakis(phenylethynyl)be- nzene,
1,2,4,5-tetrakis(phenylethynyl)benzene,
1,2,3,4,5-pentakis(phenylet- hynyl)benzene, and
1,2,3,4,5,6-hexakis(phenylethynyl)benzene.
[0032] The choice of organic compound can influence the yield and
nature of the carbon nanotubes, as well as the processing window of
the precursor composition. Phenyl groups may increase the yield of
carbon nanotubes because they may be easily incorporated into a
growing carbon nanotube. 1,2,4,5-Tetrakis(phenylethynyl)benzene has
a symmetrical structure that may allow for incorporation of more
rings than some other phenyl compounds.
[0033] The compounds of the precursor composition can be combined
in any way in which the heating step results in the formation of
carbon nanotubes. Suitable methods include, but are not limited to,
mechanical mixing, solvent mixing, and partial complexation.
Partial complexation refers to forming metal-ethynyl complex groups
from a portion of the ethynyl groups in the ethynyl compound. The
result is a combination of compounds, as described above, that are
already mixed. Precursor compositions having a single compound may
not require mixing.
[0034] Heating Step
[0035] In the heating step, the precursor composition is heated
under conditions effective to produce carbon nanotubes. The heating
can be done in an inert atmosphere. Other heating conditions may
produce a polymer composition or a carbon nanoparticle composition.
Compositions containing combinations of any of polymer, carbon
nanoparticles, and carbon nanotubes are possible.
[0036] A number of processes may occur during the heating step,
including melting, crosslinking, degradation, metal nanoparticle
formation, carbonization, carbon nanoparticle formation, and carbon
nanotube formation. The sequence of the processes may change and
various processes may occur simultaneously. Any descriptions of
reaction mechanisms are proposed mechanisms that do not limit the
scope of the claimed processes.
[0037] Initially, the precursor composition, if a solid, may melt.
Alternatively, a liquid precursor composition may become less
viscous. In either case, diffusion through the precursor
composition may be enhanced. The viscosity of the melt, as well as
the time that the precursor composition remains a melt may affect
the properties of the carbon nanotube composition. Precursor
compositions containing a high percentage of metal may not melt at
all. This may result in a powdered carbon nanotube composition.
[0038] At low temperatures, crosslinking may occur between the
non-complexed ethynyl groups in the organic compound. This converts
the organic compound into a polymer. Crosslinking, as used herein,
refers to a reaction joining one ethynyl group to another, whether
the result is an oligomer, a linear polymer, or a thermoset. The
reaction is considered crosslinking if an ethynyl groups reacts
with at least one other ethynyl group. The entire composition may
then be referred to as a polymer composition. When the organic
compound has multiple ethynyl group capable of crosslinking, the
polymer composition may be a thermoset. Crosslinking may begin at
about 250.degree. C. Heat treatment to about 400.degree. C. may
result in virtually no remaining ethynyl groups, in that they are
all crosslinked. There may be little weight loss due to the
crosslinking, but there may be some shrinking. Crosslinking can be
important because it can make the composition into a solid
material. Examples 20-32 illustrate the production of polymer
compositions, including thermosets.
[0039] Another process that may occur during heating is that the
metallocenyl group, metal salt, and/or metal-ethynyl complex group
may decompose, releasing elemental metal. The elemental metal may
coalesce into metal nanoparticles. Metal nanoparticles may begin to
form at about 350.degree. C. The size of the metal nanoparticles
may depend on the mobility of the metal atoms, which in turn may
depend on the viscosity of the precursor composition and the
heating conditions. It is also possible for some or all of the
elemental metal to not coalesce and remain as elemental metal.
[0040] Metallocenyl groups may tend to degrade at lower
temperatures, such as about 300.degree. C. Some metallic compounds
may degrade even below the melting point of the precursor
composition. Some metal salts and metal-ethynyl complex groups may
degrade at higher temperatures. This may affect the size of the
metal nanoparticles. A metal salt or a metal-ethynyl complex group
may degrade after crosslinking is complete and the composition is a
solid thermoset. This may reduce the mobility of the metal atoms
and form smaller nanoparticles.
[0041] A metallocenyl group may degrade before crosslinking is
complete while the composition has low viscosity. The metal atoms
may have higher mobility in this low viscosity composition and form
larger nanoparticles. However, if the heating is fast enough, a
thermoset may form before the metal nanoparticles have time to grow
in size.
[0042] After the metal-ethynyl complex groups degrade, more ethynyl
groups may be available for crosslinking, increasing the viscosity
of the composition. This may also occur simultaneously with
carbonization.
[0043] If the composition is only heated enough to form the polymer
composition, but not a carbon nanoparticle or nanotube composition,
the polymer composition may be a magnetic polymer, depending on the
metal component. The magnetic polymer may contain metal
nanoparticles and/or elemental metal in an insulating matrix. The
magnetic polymers may retain excellent structural integrity and
high thermal stability. Different polymers with various
concentrations and metal particle sizes may have distinct
properties, which would be expected to affect the characteristics
of the final metal containing systems. Alternatively, the polymer
composition may be a conducting polymer. This can occur when the
metal concentration is high enough that transport can occur among
the metal nanoparticles and/or elemental metal.
[0044] Carbonization may occur when the heating is continued. This
may cause the formation of carbon nanotubes and/or carbon
nanoparticles. These processes may occur at or above a temperature
of from about 500.degree. C. to about 1600.degree. C. The amount of
carbon nanotubes and carbon nanoparticles produced can be affected
by the reactants, the heating conditions, and the properties of the
metal nanoparticles.
[0045] Examples 33-35 illustrate the formation of carbon
nanoparticles from ethynyl compounds in the absence of a metallic
compound. Despite the high temperatures used, no carbon nanotubes
were formed. Examples 36-39 illustrate the formation of carbon
nanoparticles from metal-ethynyl complexes heated to temperatures
too low to form carbon nanotubes.
[0046] Higher temperatures and/or longer heating times may be
required to form carbon nanotubes than to form carbon
nanoparticles. When the heating is sufficient, the metal
nanoparticles may catalyze the assembly of carbon nanoparticles
into carbon nanotubes. Carbon nanotubes may also grow from free
carbon or from the organic compound. Examples 40-128 illustrate the
processes of the claimed invention with a variety of compounds and
heating conditions.
[0047] The carbon nanotube composition may contain up to 75% by
weight or more carbon nanotubes. The carbon nanotubes may be SWNT's
or MWNT's. The diameter of the tubes may be controlled by the size
of the metal nanoparticles. Larger metal nanoparticles may result
in larger diameter carbon nanotubes, such as MWNT's. The carbon
nanotubes can be in an amorphous carbon, graphite, or highly
ordered carbon domain depending on the heating conditions. The
carbon nanotube composition may also comprise any of carbon
nanoparticles, amorphous carbon, metal nanoparticles, and elemental
metal.
[0048] The carbon nanotube composition may have magnetic properties
that are caused by the metal, the carbon nanotubes, or both. The
carbon nanotube composition may be a magnetic semiconductor. In
some cases, metal may react with the carbon nanotubes, the carbon
nanoparticles, or the carbon domain. Examples 84, 85, 89-91, 94-96,
and 100 illustrate cases where very little free metal was observed.
The metal may have reacted with carbon, including intercalation of
metal atoms and/or nanoparticles into the lattice of the carbon
nanotubes.
[0049] The presence of carbon nanotubes can be confirmed by Raman
spectroscopy (FIGS. 1 and 2), x-ray diffraction (FIG. 3), HRTEM,
and HRSEM. The following diffraction peaks are observed in a x-ray
diffraction scan taken with CuK.alpha. radiation.
1 2.theta. hkl d (.ANG.) 25.94 111 3.4347 42.994 220 2.1036 53.335
222 1.7940 78.798 422 1.2145
[0050] The above diffraction peaks in a x-ray scan are known in the
art to be the fingerprints for the presence of carbon nanotubes.
The diameters of the carbon nanotubes can be estimated from the
FWHM of the peaks and the Scherrar equation. From the diameters
obtained, one can deduce whether the carbon nanotubes are
single-walled or multi-walled. In cobalt-based samples, a diameter
of .apprxeq.4 nm can be obtained, suggesting the presence of
SWNT's. This result can be corroborated with a scanning electron
micrograph obtained on a HRSEM.
[0051] Alternative Process
[0052] An alternative process comprises the steps of providing a
precursor composition comprising a polymer and a metallic component
and heating the precursor composition under conditions effective to
produce carbon nanotubes. Examples 41, 42, 44, and 47 illustrate
the alternative process.
[0053] The precursor composition of this process can be similar to
the polymer composition. The precursor composition comprises a
polymer having crosslinked ethynyl groups and a metallic component.
The polymer can be a linear polymer or a thermoset. The metallic
component can be the same as those found in the metallic compound
and the decomposition products thereof. The metallic component can
be selected from, but is not limited to, a metallocenyl group, a
metal-ethynyl complex group, a metal salt, metal nanoparticles, and
elemental metal. The metallocenyl group and the metal-ethynyl
complex group may be bonded to the polymer or found in compounds
combined with the polymer. Combined can refer to, but is not
limited to, the compound or component being mixed, embedded, or
dispersed in the polymer. The metal nanoparticles and elemental
metal may be the result of degradation of metallic groups and may
be combined with the polymer, rather than bonded to it. The metal
salt may also be combined with the polymer. Combinations of these
groups are also possible.
[0054] The metal can be any metal described or recited above and
combinations thereof. The metallocenyl group can be, but is not
limited to, ferrocenyl. The metal-ethynyl complex group can be, but
is not limited to, hexacarbonyl dicobalt-ethynyl complex group,
hexacarbonyl diiron-ethynyl complex group, nonacarbonyl
triruthenium-ethynyl complex group, and combinations thereof. The
metal salt can be, but is not limited to, metal carbonyl salt,
nonacarbonyl diiron, octacarbonyl dicobalt, dodecacarbonyl
triruthenium, hexacarbonyl tungsten, a phosphine metal salt,
bis(triphenylphosphine)nickel, bis(triethylphosphine)palladiu- m,
bis(triethylphosphine)platinum, dicarbonyl
bis(triphenylphosphine)nicke- l, palladium (II) acetylacetonate,
manganese (III)-2,4-pentanedionate, cyclopentadienyl tungsten
tricarbonyl dimer, and combinations thereof. The metal
nanoparticles and elemental metal can comprise any metal described
or recited above and combinations thereof.
[0055] Carbon Nanotube Compositions
[0056] The invention also comprises a carbon nanotube composition
comprising carbon nanotubes and metal nanoparticles and/or
elemental metal, wherein the carbon nanotube composition is rigid.
"Elemental metal" refers to individual atoms of metal. The term
"rigid" is used to describe a coherent, solid, substantially
nonporous mass that undergoes little elastic deformation, but can
fracture when enough stress is applied. A thin fiber or film of the
carbon nanotube composition may be slightly bendable, but is
brittle rather than flexible. This is in contrast to a powder or a
crumbly material, which is not cohesive. It also differs from a
rubbery material, which undergoes elastic deformation. It also
differs from a paper-like material, which is flexible.
[0057] The rigid carbon nanotube composition may be made by, but is
not limited to, the processes of the present invention. Precursor
compositions that melt can result in a rigid carbon nanotube
composition. When the precursor composition does not melt, the
resulting carbon nanotube composition may be soft or powdery.
[0058] Although not necessarily always the case, the carbon
nanotube composition may have some MWNT's on the surface and mostly
SWNT's in the interior. In some of the Examples the average
diameter of the carbon nanotubes was about 4-6 nm, confirming that
most of the carbon nanotubes were SWNT's. In some of the Examples
the lattice parameter of the tubes was about a=5.9-6.0 .ANG.. This
is in contrast to the lattice parameters of graphite, which are
typically about a=2.5 .ANG. and c=10.0 .ANG..
[0059] It is possible for the carbon nanotube composition to be a
magnetic semiconductor. The carbon nanotube composition may also be
superconductor.
[0060] It is possible to make a shaped article that contains carbon
nanotubes made in situ in the article. Processes using compounds
having one or more ethynyl groups and/or metal ethynyl complex
groups may be shaped. This is because such organic compounds may
form a thermoplastic or thermoset. If the precursor composition is
a liquid, it can be formed into the desired shape before or during
heating, but before formation of a solid polymer or carbon nanotube
composition, as the shape may then be fixed. A solid precursor
composition may be melted before forming into a shape or may be
pressed into a shape. The possible shapes include, but are not
limited to, a solid article, a film, and a fiber. A fiber can be
formed by drawing the fiber from the melt state, followed by carbon
nanotube formation. A composite comprising the carbon nanotube
composition may be made by impregnating fibers with the precursor
composition, followed by carbon nanotube formation. In another type
of composite, the carbon nanotubes are the fiber that is
impregnated with another polymer. Other types of composites may
also be made.
[0061] A film of the carbon nanotube composition may comprise a
plurality of layers containing different concentrations of carbon
nanotubes. One way to make this is to use a plurality of precursor
compositions comprising different concentrations of compounds
and/or different metallic compounds and organic compounds. The
precursor compositions are cast in adjacent layers before formation
of the carbon nanotube composition. This can be done from a melt or
from a solution.
[0062] The carbon nanotube compositions may have useful structural,
catalytic, electric, medical, or magnetic properties, making them
useful for many applications. The electromagnetic properties may be
due to the presence of the metal, the carbon nanotubes, or
both.
[0063] A drug delivery system comprising the carbon nanotube
composition may be made. This may be done by grinding the carbon
nanotube composition to a powder and mixing the powder with the
drug, or dispersing the carbon nanotube composition in solution
with a drug. The drug can adsorb into the carbon nanotubes. A
suspension of the powder with the drug can then be injected or
otherwise placed into a patient. The magnetic properties of the
carbon nanotube composition may allow for the movement of a drug
through a patient by external application of magnetic fields. The
drug composition can thereby be contained in a specific region of
the body. Over time, the drug composition may decompose, releasing
the drug in the region slowly and over an extended period, without
exposing the entire body to the drug. This may be useful in the
treatment of tumors by chemotherapy. Drugs can be contained in a
tumor over an extended period, without causing toxic effects in the
rest of the body. Drugs can also be directed to an area of
excessive bleeding to stop the bleeding. Such systems using other
materials are known in the art.
[0064] A lubricant comprising the carbon nanotube composition may
also be made. Carbon nanotubes are able to easily slide against
each other and thus they are also expected to have lubricating
properties. The carbon nanotube composition can be ground to a
powder or otherwise dispersed and possibly mixed with other
ingredients to make a lubricant.
[0065] A microelectronic device comprising the carbon nanotube
composition may be made. One possible method to make the
microelectronic device is to make an ink comprising the precursor
composition or the carbon nanotube composition. The ink can be
applied to the device by any means for forming a pattern from an
ink. Such means are known in the art. If the ink comprises the
precursor composition, the device can then be heated to produce
carbon nanotube circuit elements in a desired pattern. Such a
device may take advantage of potentially asymmetric electrical and
magnetic properties of the carbon nanotubes.
[0066] An electrode comprising the carbon nanotube composition may
also be made. One possible method to make the electrode is to grind
the carbon nanotube composition to a powder or otherwise disperse
the carbon nanotubes. The carbon nanotubes may then be deposited on
a substrate by methods known in the art. Alternatively, the
electrode can be made at the same time as the carbon nanotube
composition by forming the carbon nanotube composition as a shaped
article in the shape of the electrode. The electrode can be a fuel
cell electrode. Fuel cell electrodes are known in the art and may
contain carbon and platinum on a membrane. The carbon nanotube
composition may already contain sufficient platinum from the
metallic compound or additional platinum may be deposited into the
composition. The carbon nanotube composition may be deposited on a
fuel cell membrane by methods known in the art, or may be made in
situ on the membrane.
[0067] A ferrofluid comprising the carbon nanotube composition may
be made. A ferrofluid is fluid with magnetic properties. The flow
of a ferrofluid may be influenced by an applied magnetic field. One
possible way to make the ferrofluid is to grind the carbon nanotube
composition to a powder and place the powder into a colloidal
solution. The magnetic properties may come from the metal, the
carbon nanotubes, or both.
[0068] Devices that can be made from the carbon nanotube
composition include, but are not limited to, electrical components,
including fibers and films; magnetic components; sensors;
photovoltaic devices; and batteries. Any of these devices may
include an electrical or magnetic component made as a shaped
article of the carbon nanotube composition, or can be made from
already formed carbon nanotube composition. The designs of such
devices are known in the art.
[0069] Having described the invention, the following examples are
given to illustrate specific embodiments of the invention. These
specific examples are not intended to limit the scope of the
invention described in this application.
[0070] I. Synthesis of Compounds
[0071] A. Synthesis of Metallocenyl Compounds
EXAMPLE 1
[0072] Synthesis of
1,3-bis(ferrocenylethynyl)benzene--1,3-Bis(ferrocenyle-
thynyl)benzene was prepared by the palladium-catalyzed coupling
reaction using 520 mg (2.48 mmol) of ethynylferrocene, 389 mg (1.18
mmol) of 1,3-diiodobenzene, 13.3 mg (0.059 mmol) Pd(OAc).sub.2,
46.4 mg (0.177 mmol) of PPh.sub.3, and 5.6 mg (0.030 mmol) of CuI
in 25 mL tetrahydrofuran, 5 mL pyridine, and 5 mL diisopropylamine
at 25.degree. C. The residue was purified using a 5:1
hexane/CH.sub.2Cl.sub.2 solvent mixture to afford 526 mg (82%) of
an orange solid, m.p. 225.degree. C., identified as the desired
product.
EXAMPLE 2
[0073] Synthesis of
1,4-bis(ferrocenylethynyl)benzene--1,4-Bis(ferrocenyle-
thynyl)benzene was prepared by the palladium-catalyzed coupling
reaction using 500 mg (2.38 mmol) of ethynylferrocene, 314 mg
(0.952 mmol) of 1,4-diiodobenzene, 10.7 mg (0.0476 mmol)
Pd(OAc).sub.2, 37.3 mg (0.143 mmol) of PPh.sub.3, and 3.6 mg (0.019
mmol) of CuI in 25 mL tetrahydrofuran, 5 mL pyridine, and 5 mL
diisopropylamine at 25.degree. C. The residue was purified using a
2:1 hexane/CH.sub.2Cl.sub.2 solvent mixture to afford 343 mg (73%)
of an orange solid, m.p. 257.degree. C., identified as the desired
product.
EXAMPLE 3
[0074] Synthesis of
1-(ferrocenylethynyl)-3-(phenylethynyl)benzene--1-(Fer-
rocenylethynyl)-3-(phenylethynyl)benzene was prepared by the
palladium-catalyzed coupling reaction using 500 mg (1.37 mmol) of
1-(ferrocenylethynyl)-3-bromobenzene, 210 mg (2.05 mmol) of
phenylacetylene, 15.4 mg (0.0686 mmol) Pd(OAc).sub.2, 53.9 mg
(0.206 mmol) of PPh.sub.3, and 2.6 mg (0.0137 mmol) of CuI in 25 mL
tetrahydrofuran, 5 mL pyridine, and 5 mL diisopropylamine at
60.degree. C. The residue was purified using a 5:1
hexane/CH.sub.2Cl.sub.2 solvent mixture to afford 442 mg (84%) of
an orange-red solid, m.p. 181.degree. C., identified as the desired
product.
EXAMPLE 4
[0075] Synthesis of
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene--1-(Fer-
rocenylethynyl)-4-(phenylethynyl)benzene was prepared by the
palladium-catalyzed coupling reaction using 500 mg (1.37 mmol) of
1-(ferrocenylethynyl)-4-bromobenzene, 210 mg (2.05 mmol) of
phenylacetylene, 15.4 mg (0.0686 mmol) Pd(OAc).sub.2, 53.9 mg
(0.206 mmol) of PPh.sub.3, and 2.6 mg (0.0137 mmol) of CuI in 25 mL
tetrahydrofuran, 5 mL pyridine, and 5 mL diisopropylamine at
60.degree. C. The residue was purified using a 5:1
hexane/CH.sub.2Cl.sub.2 solvent mixture to afford 385 mg (73%) of
an orange-red solid, m.p. 198.degree. C., identified as the desired
product.
EXAMPLE 5
[0076] Synthesis of
bis(ferrocenylethynyl)-bis(triphenylphosphine)nickel---
Ethynylferrocene (0.3495 g, 1.66 mmol) was placed in a 250 mL round
bottom flask with a side arm and cooled to -78.degree. C. At this
time, 1.6 mL of 1.6 molar n-BuLi was added with stirring for 1 hr
while warming to room temperature. The solution was then cooled to
-78.degree. C. and NiCl.sub.2(PPh.sub.3).sub.2 (0.544 g, 0.83 mmol)
in 20 mL of dry THF was added by cannula. The reaction mixture was
allowed to warm to room temperature and stirred overnight. Upon
removal of solvent at reduced pressure, the desire black product
was isolated.
EXAMPLE 6
[0077] Synthesis of
bis(ferrocenylethynyl)-bis(triethylphosphine)palladium-
--Ethynylferrocene (0.3448 g, 1.64 mmol) was placed in a 250 mL
round bottom flask with a side arm and cooled to -78.degree. C. At
this time, 0.74 mL of n-BuLi (0.95 equivalent) was added with
stirring for 1 hr while warming to room temperature. The solution
was then cooled to -78.degree. C. and PdCl.sub.2(PEt.sub.3).sub.2
(0.34 g, 0.82 mmol) in 20 mL of dry THF was added by cannula. The
brown reaction mixture was allowed to warm to room temperature and
stirred overnight. Upon removal of solvent at reduced pressure, the
desire brown product was isolated.
[0078] B. Synthesis of Metal-Ethynyl Complexes
EXAMPLE 7
[0079] Synthesis of 1:1 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Co.sub.2(CO).sub.8 (100 mg,
0.292 mmol) and 20 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (140 mg, 0.292
mmol) dissolved in 15 mL of methylene chloride was added by syringe
and the resulting brown mixture was again evacuated and purged with
argon three times. The mixture was allowed to warm to room
temperature, resulting in a color change to dark green, and stirred
3 hr. The formation of the green solution is apparently due to the
reaction of the Co.sub.2(CO).sub.8 with an alkyne group of
1,2,4,5-tetrakis(phenylethynyl)benzene.
EXAMPLE 8
[0080] Synthesis of 1:3 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Co.sub.2(CO).sub.8 (0.5 g,
1.46 mmol) and 75 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (2.1 g, 4.38
mmol) dissolved in 100 mL of methylene chloride was added by
syringe resulting in the formation of a white precipitate. The
yellowish-brown mixture was allowed to warm to room temperature and
was stirred for 3 hr resulting in dissolution of the solid and a
color change to dark green. The formation of the green solution is
apparently due to the reaction of the Co.sub.2(CO).sub.8 with an
alkyne group of 1,2,4,5-tetrakis(phenylethynyl- )benzene. The
solvent was removed at reduced pressure. The product was used as
prepared for characterization studies.
EXAMPLE 9
[0081] Synthesis of 1:10 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Co.sub.2(CO).sub.8 (0.2 g,
0.58 mmol) and 75 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (2.8 g, 5.8
mmol) dissolved in 100 mL of methylene chloride was added by
syringe resulting in the formation a white precipitate. The mixture
was allowed to warm to room temperature and was stirred for 3 hr
resulting in dissolution of the solid and a color change to dark
green. The formation of the green solution is apparently due to the
reaction of the Co.sub.2(CO).sub.8 with an alkyne group of
1,2,4,5-tetrakis(phenylethynyl)benzene. The solvent was removed at
reduced pressure. The product was used as prepared for
characterization studies.
EXAMPLE 10
[0082] Synthesis of 1:15 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Co.sub.2(CO).sub.8 (0.1 g,
0.29 mmol) and 75 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (2.1 g, 4.4
mmol) dissolved in 100 mL of methylene chloride was added by
syringe resulting in the formation a white precipitate. The mixture
turned yellow, was allowed to warm to room temperature, and was
stirred for 3 hr resulting in dissolution of the solid and a color
change to dark green. The formation of the green solution is
apparently due to the reaction of the Co.sub.2(CO).sub.8 with an
alkyne group of 1,2,4,5-tetrakis(phenylethynyl)benzene. The solvent
was removed at reduced pressure. The product was used as prepared
for characterization studies.
EXAMPLE 11
[0083] Synthesis of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Co.sub.2(CO).sub.8 (0.1 g,
0.29 mmol) and 75 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (2.8 g, 5.8
mmol) dissolved in 100 mL of methylene chloride was added by
syringe resulting in the formation a white precipitate. The mixture
turned yellow, was allowed to warm to room temperature, and was
stirred for 3 hr resulting in dissolution of the solid and a color
change to dark green. The formation of the green solution is
apparently due to the reaction of the Co.sub.2(CO).sub.8 with an
alkyne group of 1,2,4,5-tetrakis(phenylethynyl)benzene. The solvent
was removed at reduced pressure. The product was used as prepared
for characterization studies.
EXAMPLE 12
[0084] Synthesis of 1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Co.sub.2(CO).sub.8 (0.1 g,
0.29 mmol) and 75 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (7.0 g, 14.6
mmol) dissolved in 175 mL of methylene chloride was added by
syringe resulting in the formation a white precipitate. The mixture
turned dark brown, was allowed to warm to room temperature, and was
stirred for 3 hr resulting in dissolution of the solid and a color
change to dark green. The formation of the green solution is
apparently due to the reaction of the Co.sub.2(CO).sub.8 with an
alkyne group of 1,2,4,5-tetrakis(phenylethynyl- )benzene. The
solvent was removed at reduced pressure. The product was used as
prepared for characterization studies.
EXAMPLE 13
[0085] Synthesis of 1:1 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Fe.sub.2(CO).sub.9 (0.17 g,
0.47 mmol) and 25 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (0.22 g, 0.46
mmol) dissolved in 25 mL of methylene chloride was added by syringe
resulting in the formation a white precipitate. The mixture was
allowed to warm to room temperature and stirred for 3 hr resulting
in a color change to dark red. The formation of the red solution is
apparently due to the reaction of the Fe.sub.2(CO).sub.9 with an
alkyne group of 1,2,4,5-tetrakis(phenyleth- ynyl)benzene. The
solvent was removed at reduced pressure. The product was used as
prepared for characterization studies.
EXAMPLE 14
[0086] Synthesis of 1:5 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Fe.sub.2(CO).sub.9 (0.202
g, 0.55 mmol) and 25 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (1.31 g, 2.74
mmol) dissolved in 25 mL of methylene chloride was added by syringe
resulting in the formation a white precipitate. The mixture was
allowed to warm to room temperature and stirred for 3 hr resulting
in a color change to dark red. The formation of the red solution is
apparently due to the reaction of the Fe.sub.2(CO).sub.9 with an
alkyne group of 1,2,4,5-tetrakis(phenyleth- ynyl)benzene. The
solvent was removed at reduced pressure. The product was used as
prepared for characterization studies.
EXAMPLE 15
[0087] Synthesis of 1:10 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Fe.sub.3(CO).sub.12 (0.11
g, 0.20 mmol) and 60 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (0.98 g, 1.99
mmol) dissolved in 70 mL of methylene chloride was added by syringe
resulting in the formation a white precipitate. The mixture was
allowed to warm to room temperature and stirred for 3 hr resulting
in a color change to dark red. The formation of the red solution is
apparently due to the reaction of the Fe.sub.3(CO).sub.12 with an
alkyne group of 1,2,4,5-tetrakis (phenylethynyl)benzene. The
solvent was removed at reduced pressure. The product was used as
prepared for characterization studies.
EXAMPLE 16
[0088] Synthesis of 1:15 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Fe.sub.2(CO).sub.9 (0.11 g,
0.27 mmol) and 50 mL of dry hexane were added to a 100 mL round
bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1,2,4,5-Tetrakis(phenylethynyl)benzene (1.97 g, 4.12
mmol) dissolved in 90 mL of methylene chloride was added by syringe
resulting in a yellow solution and the formation a white
precipitate. The mixture was allowed to warm to room temperature
and stirred for 2.5 hr resulting in dissolution of the solid and
the formation of an orange homogeneous solution. The formation of
the orange solution is apparently due to the reaction of the
Fe.sub.2(CO).sub.9 with an alkyne group of
1,2,4,5-tetrakis(phenylethynyl)benzene. The solvent was removed at
reduced pressure. The pale red solid product was used as prepared
for characterization studies.
EXAMPLE 17
[0089] Synthesis of 1:10 nonacarbonyltriruthenium complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--Ru.sub.3(CO).sub.12 (0.14
g, 0.22 mmol) and tetrakis(phenylethynyl)benzene (1.04 g, 2.18
mmol), and 100 mL of ethanol were added to a 250 mL round bottomed
flask. While stirring, the mixture was heated to reflux for 10 hr
resulting in the formation of a brown solution. The solvent was
removed at reduced pressure. The product as obtained was used as
prepared for characterization studies.
EXAMPLE 18
[0090] Synthesis of 1:1 hexacarbonyldicobalt complex of
1,4-bis(ferrocenyl)butadiyne--Co.sub.2(CO).sub.8 (0.17 g, 0.50
mmol) and 30 mL of dry hexane were added to a 100 mL round bottomed
flask. While stirring, the mixture was cooled to -78.degree. C.,
evacuated, and purged with argon three times to remove air.
1,4-Bis(ferrocenyl)butadiyne (0.21 g, 0.50 mmol) dissolved in 30 mL
of methylene chloride was added by syringe. The mixture turned
orange, was allowed to warm to room temperature, and was stirred
for 3 hr resulting in a color change to dark brown. The solvent was
removed at reduced pressure. The black product was used as prepared
for characterization studies.
EXAMPLE 19
[0091] Synthesis of 1:1 hexacarbonyldicobalt complex of
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene--Co.sub.2(CO).sub.8
(0.053 g, 0.16 mmol) and 25 mL of dry hexane were added to a 100 mL
round bottomed flask. While stirring, the mixture was cooled to
-78.degree. C., evacuated, and purged with argon three times to
remove air. 1-(Ferrocenylethynyl)-4-(phenylethynyl)benzene (0.062
g, 0.16 mmol) prepared as in Example 4 dissolved in 25 mL of
methylene chloride was added by syringe. The mixture turned orange,
was allowed to warm to room temperature, and was stirred for 4.5
hr. The formation of the orange solution is apparently due to the
reaction of the Co.sub.2(CO).sub.8 with an ethynyl group of
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene. The solvent was
removed at reduced pressure. The black product was used as prepared
for characterization studies.
[0092] II. Formation of Polymer Composition
[0093] A. General
EXAMPLE 20
[0094] Formation of polymer compositions as precursors to carbon
nanotubes--Polymer compositions can be obtained from the
compositions described above that are thermally cured to a
thermoset. If the composition melts or is a liquid, shaped
components (films, fibers, and solids with various configurations)
can be readily obtained containing carbon nanotubes. The key to
carbon nanotube formation is the presence of at least a trace
amount of metal nanoparticles. Depending on the metal group and
ethynyl compound, the precursor systems were further heated above
300.degree. C. for various lengths of time to degrade the
metallocene or metal complex into metal nanoparticle, which is
responsible for the formation of carbon nanotubes. Some of the
systems that contained larger amounts of metal nanoparticles showed
magnetic properties due to the metal nanoparticles as determined by
their attraction to a bar (permanent) magnet. Some metal
nanoparticles that are responsible for the formation of the carbon
nanotubes are nonmagnetic. For example, the observations indicate
that the metallocenes, metal complexes of the acetylene moieties,
and other organometallic systems decomposes or degrades above
300.degree. C. resulting in the deposition of metal nanoparticles
in the various thermosetting compositions.
[0095] B. Formation of Polymer Composition from an Ethynyl
Compound
EXAMPLE 21
[0096] Polymerization of
1,2,4,5-Tetrakis(phenylethynyl)benzene--The monomer (0.26 g) was
weighed into an aluminum planchet and cured by heating in air at
200.degree. C. for 1 hour, at 225.degree. C. for 2 hours, and at
275.degree. C. for 1 hour resulting in solidification. Almost
immediately after melting, the monomer started to darken. Within 45
minutes, the melt had become fairly viscous. After heating at
275.degree. C., the polymer had not loss any weight. The polymer
was removed from the planchet and used for characterization
studies. An infrared spectrum showed the absence of an absorption
centered at 2212 cm.sup.-1 attributed to an acetylenic
carbon-carbon triple bond.
[0097] C: Formation of Polymer Composition from Metallocenyl
Compound that is also an Ethynyl Compound
EXAMPLE 22
[0098] Polymerization of
1,4-bis(ferrocenyl)butadiyne--1,4-Bis(ferrocenyl)- butadiyne (14.1
mg) was placed in a TGA/DTA chamber and heated under a nitrogen
atmosphere at 10.degree. C./min to 1000.degree. C. The sample
melted at about 203.degree. C. followed by the immediate conversion
to a thermoset as determined from an exotherm at 259.degree. C.
Between 350 and 500.degree. C., the sample lost about 30% of its
weight attributed to volatilization and the formation of an iron
nanoparticle composition. Further heating above 500.degree. C.
resulted in carbonization and the homogeneous formation of an iron
nanoparticle carbon composition. At 1000.degree. C., the sample
retained 64% of the original weight and was magnetic as determined
from the attraction to a bar (permanent) magnet.
EXAMPLE 23
[0099] Polymerization of
1,3-bis(ferrocenylethynyl)benzene--1,3-Bis(ferroc-
enylethynyl)benzene (16.8 mg) prepared in Example 1 was weighed
into a TGA boat and polymerized by heating under a nitrogen
atmosphere at 225.degree. C. for 5 min, at 300.degree. C. for 30
min, and at 350.degree. C. for 30 min, resulting in the formation
of a solid, black thermoset material. During the heat-treatment,
the sample lost about 11% of its weight. An FTIR spectrum of the
polymer composition showed the absence of the acetylenic
carbon-carbon triple bond absorption at 2215 cm.sup.-1.
EXAMPLE 24
[0100] Polymerization of
1,4-bis(ferrocenylethynyl)benzene--1,4-Bis(ferroc-
enylethynyl)benzene (13.7 mg) prepared in Example 2 was weighed
into a TGA boat and polymerized by heating under a nitrogen
atmosphere at 225.degree. C. for 5 min, at 300.degree. C. for 30
min and at 350.degree. C. for 30 min, resulting in the formation of
a solid, black thermoset material. During the heat-treatment, the
sample lost about 16% of its weight. An FTIR spectrum of the
polymer composition showed the absence of the acetylenic
carbon-carbon triple bond absorptions at 2224 and 2202
cm.sup.-1.
EXAMPLE 25
[0101] Polymerization of
1-(ferrocenylethynyl)-3-(phenylethynyl)benzene--1-
-(Ferrocenylethynyl)-3-(phenylethynyl)benzene (15.1 mg) prepared in
Example 3 was weighed into a TGA boat and polymerized by heating
under a nitrogen atmosphere at 225.degree. C. for 5 min, at
300.degree. C. for 30 min and at 350.degree. C. for 30 min,
resulting in the formation of a solid thermoset material. During
the heat-treatment, the sample lost about 12% of its weight. An
FTIR spectrum of the polymer composition showed the absence of the
acetylenic carbon-carbon triple bond absorption at 2212
cm.sup.-1.
EXAMPLE 26
[0102] Formation of polymeric fibers from
1-(ferrocenylethynyl)-3-(phenyle-
thynyl)benzene--1-(Ferrocenylethynyl)-3-(phenylethynyl)benzene (0.5
g) prepared as in Example 3 was weighed into an aluminum planchet
and heated at 275-300.degree. C. resulting in an increase in
viscosity. Before gelation or solidification occurred, a glass rod
was pushed into the thick composition and removed resulting in the
formation of a fibrous glassy material. These results indicate that
fibers could be formed from the viscous material, thermally cured
to a shaped fiber, and further heat-treated at elevated
temperatures resulting in the formation of fibrous materials with
magnetic properties.
EXAMPLE 27
[0103] Polymerization of
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene--C- ompound
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene (15.1 mg) prepared
in Example 4 was weighed into a TGA boat and polymerized by heating
under a nitrogen atmosphere at 225.degree. C. for 5 min, at
300.degree. C. for 30 min, and at 350.degree. C. for 30 min,
resulting in the formation of a solid thermoset material. During
the heat-treatment, the sample lost about 18% of its weight. An
FTIR spectrum of the polymer composition showed the absence of the
acetylenic carbon-carbon triple bond absorption at 2203
cm.sup.-1.
[0104] D. Formation of Polymer Composition from a Metal-Ethynyl
Complex
EXAMPLE 28
[0105] Formation of polymeric fibers from 1:20 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene--A sample of 1:20
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (0.5 g) prepared as in
Example 11 was weighed into an aluminum planchet and heated at
275.degree. C. resulting in an increase in viscosity. Before
gelation or solidification occurred, a glass rod was pushed into
the thick composition and removed resulting in the formation of a
fibrous glassy material. These results indicate that fibers could
be formed from the viscous material, thermally cured to a shaped
fiber, and further heat-treated at elevated temperatures resulting
in the formation of fibrous materials with magnetic properties.
EXAMPLE 29
[0106] Formation of polymeric fibers from 1:15 hexacarbonyldiiron
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene--The 1:15
hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (0.1 g) prepared as in
Example 10 was weighed into an aluminum planchet and heated at
275.degree. C. resulting in an increase in viscosity. Before
gelation or solidification occurred, a glass rod was pushed into
the thick composition and removed resulting in the formation of a
fibrous glassy material. Further heat-treatment resulted in
gelation to a solid fiber. These results indicate that fibers could
be formed from the viscous material, thermally cured to a shaped
fiber, and further heat-treated at elevated temperatures resulting
in the formation of fibrous polymeric materials.
[0107] E. Formation of Polymer Composition from a Metallocenyl
Compound and an Ethynyl Compound
EXAMPLE 30
[0108] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to iron nanoparticle
thermoset composition by heating at 400.degree. C. for 12 hour--A
50/50 molar mixture (20.42 mg) of 1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 400.degree. C. and
held at 400.degree. C. for 12 hour. The iron nanoparticle thermoset
composition retained 93% of its original weight and was attracted
to a bar (permanent) magnet, indicating ferromagnetic behavior.
X-ray diffraction studies did not show the formation of carbon
nanotubes but did show the formation of iron nanoparticles.
EXAMPLE 31
[0109] Formation of polymeric fibers from 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene--- A mixture prepared from
0.25 g of 1,4-bis(ferrocenyl)butadiyne and 0.28 g of
1,2,4,5-tetrakis(phenylethynyl)benzene was ground with a mortar
& pestle and thoroughly mixed. The mixture was transferred to
an aluminum planchet and heated at 225-300.degree. C. resulting in
an increase in viscosity. Before gelation or solidification
occurred, a glass rod was pushed into the thick composition and
removed resulting in the formation of a fibrous glassy material.
Further heating of the fiber resulted in gelation or
solidification. These results indicate that fibers could be formed
from the viscous material, thermally cured to a shaped fiber, and
further heat-treated at elevated temperatures resulting in the
formation of fibrous materials with magnetic properties.
[0110] F. Formation of Polymer Composition from a Metal-Ethynyl
Complex and an Ethynyl Compound
EXAMPLE 32
[0111] Formation of polymeric fibers from 50/50 weight mixture of
1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1,2,4,5-tetrakis(phenylethynyl)benzene--A 50/50 weight mixture (0.3
g) of 1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl- )benzene prepared in Example 12 and
1,2,4,5-tetrakis(phenylethynyl)benzene was weighed into an aluminum
planchet and heated at 275.degree. C. resulting in an increase in
viscosity. Before gelation or solidification occurred, a glass rod
was pushed into the thick composition and removed resulting in the
formation of a fibrous glassy material. These results indicate that
fibers could be formed from the viscous material, thermally cured
to a shaped fiber, and further heat-treated at elevated
temperatures resulting in the formation of fibrous materials with
magnetic properties.
[0112] III. Formation of Carbon Nanoparticle Composition
[0113] A. Formation of Carbon Nanoparticle Composition from an
Ethynyl Compound
EXAMPLE 33
[0114] Conversion of 1,2,4-tris(phenylethynyl)benzene and
conversion into carbon nanoparticles--The monomer (13.3 mg) was
weighed into a TGA boat and cured by heating at 200.degree. C. for
4 hours and at 250.degree. C. for 4 hours. During the
heat-treatment, the sample lost approximately 6% weight. The
polymer was then cooled. A thermogram was then determined on the
polymer between 30.degree. C. and 950.degree. C. in a flow of
nitrogen at 50 cc/min X-ray diffraction studies showed the presence
of small carbon nanoparticles centered at about 23.53 (2-Theta) in
x-ray spectrum, which appear to be precursor to carbon
nanotubes.
EXAMPLE 34
[0115] Conversion of 1,3,5-tris(phenylethynyl)benzene into carbon
nanoparticles--The monomer (10.4 mg) was weighed into a TGA boat,
polymerized, and carbonized by heating from 30 to 850.degree. C. in
nitrogen at 10.degree. C./min resulting in a char yield of 73%.
Polymerization occurred during the heat-treatment to 500.degree. C.
The monomer lost 13 wt % between 275 and 375.degree. C. Between 375
and 500.degree. C., little weight loss occurred. Carbonization
occurred during the heat-treatment above 500.degree. C. From 500 to
600.degree. C., another 10% weight loss occurred. Only a small
weight loss occurred between 600 and 850.degree. C. resulting in
carbonization. X-ray diffraction studies showed the presence of
small carbon nanoparticles centered at about 23.53 (2-Theta) in
x-ray spectrum, which appear to be precursor to carbon
nanotubes.
EXAMPLE 35
[0116] Conversion of 1,2,4,5-tetrakis(phenylethynyl)benzene into
carbon nanoparticles--1,2,4,5-Tetrakis(phenylethynyl)benzene (11.34
mg) was weighed into a pan, placed in a TGA/DTA chamber and heated
at 10.degree. C. under a nitrogen atmosphere from room temperature
to 1000.degree. C. resulting in a char yield of 81%. During the
heat-treatment, the sample melted at 197.degree. C. and immediately
started to cure as determined by an exotherm at 293.degree. C. The
sample did not commence to lose weight until about 500.degree. C.
Most of the weight loss occurred between 500-600.degree. C., which
was attributed to carbonization. X-ray diffraction studies showed
the presence of small carbon nanoparticles centered at about 23.53
(2-Theta) in the x-ray spectrum, which appear to be precursor to
carbon nanotubes.
[0117] B. Formation of Carbon Nanoparticle Composition from a
Metal-Ethynyl Complex
EXAMPLE 36
[0118] Pyrolysis of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated at 400.degree. C.--A
sample (23.83 mg) of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 11
was heated at 10.degree. C./min to 400.degree. C. and held for 4 hr
under an inert atmosphere resulting in a weight retention of 97%.
X-ray diffraction study showed the formation of mainly very small
carbon nanoparticles.
EXAMPLE 37
[0119] Pyrolysis of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 600.degree. C.--A
sample (22.34 mg) of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 11
was heated at 10.degree. C./min to 600.degree. C. under an inert
atmosphere resulting in a weight retention of 91%. X-ray
diffraction study showed the formation of mainly very small carbon
nanoparticles.
EXAMPLE 38
[0120] Pyrolysis of 1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 600.degree. C.--A
sample (17.68 mg) of 1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 12
was heated at 10.degree. C./min to 600.degree. C. under an inert
atmosphere resulting in a weight retention of 92%. X-ray
diffraction study showed the formation of mainly very small carbon
nanoparticles at a reflection value of about 23.50.
EXAMPLE 39
[0121] Pyrolysis of 1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated at 600.degree. C. for
6 hr--A sample (18.31 mg) of 1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 12
was heated at 10.degree. C./min to 600.degree. C. and held for 6 hr
under an inert atmosphere resulting in a weight retention of 75%.
X-ray diffraction study showed the formation of mainly very small
carbon nanoparticles.
[0122] IV. Formation of Carbon Nanotube Composition
[0123] A. Formation of Carbon Nanotube Composition from a
Metallocenyl Compound that is also an Ethynyl Compound
EXAMPLE 40
[0124] Polymerization and carbon nanotube formation from
1,4-bis(ferrocenyl)butadiyne--Bis(ferrocenyl)butadiyne (14.1 mg)
was placed in a TGA/DTA chamber and heated under a nitrogen
atmosphere at 10.degree. C./min to 1000.degree. C. The sample
melted at about 203.degree. C. followed by the immediate conversion
to a thermoset as determined from an exotherm at 259.degree. C.
Between 350 and 500.degree. C., the sample lost about 30% of its
weight and resulted in the formation of an iron nanoparticle
polymer composition. Above 500.degree. C., carbon nanotubes
commenced to form as determined by Raman and x-ray studies. Upon
further heating to 1000.degree. C., the sample retained 64% of the
original weight. X-ray diffraction data of carbon nanotubes in
carbon composition showed an average size of about 10 nanometers.
The x-ray diffraction study showed the four characteristic
reflection [(111), (220), (222), and (422)] values for carbon
nanotubes. The x-ray (111) reflection value was 26.08.
EXAMPLE 41
[0125] Carbon nanotube formation from
1,3-bis(ferrocenylethynyl)benzene polymer composition--The
resulting thermoset from the polymerization of
1,3-bis(ferrocenylethynyl)benzene (15.0 mg) using the procedure in
Example 23 was further heated in a TGA boat from 30 to 1000.degree.
C. at 10.degree. C./min under a nitrogen atmosphere, resulting in a
char yield of 90%. The thermoset lost 7% of its weight between 400
and 600.degree. C. The remaining 3% occurred between 600 and
1000.degree. C. Raman and x-ray studies show the formation of
carbon nanotubes and Fe nanoparticles in the carbonization bulk
composition. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes. The x-ray (111) reflection value was
26.12.
EXAMPLE 42
[0126] Carbon nanotube formation from
1,4-bis(ferrocenylethynyl)benzene polymer composition--The
resulting thermoset from the polymerization of
1,4-bis(ferrocenylethynyl)benzene (11.6 mg) using the procedure in
Example 24 was further heated in a TGA boat from 30 to 1000.degree.
C. at 10.degree. C./min under a nitrogen atmosphere, resulting in a
char yield of 88%. The thermoset lost 7% of its weight between 350
and 600.degree. C. The remaining 5% occurred between 600 and
1000.degree. C., resulting in carbon nanotube and iron nanoparticle
formation. Raman and x-ray diffraction studies show the formation
of carbon nanotubes and Fe nanoparticles in the carbonization bulk
composition. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes.
EXAMPLE 43
[0127] Conversion of 1,3,5-tris(ferrocenylethynyl)benzene to carbon
nanotube-iron nanoparticle
composition--1,3,5-Tris(ferrocenylethynyl)benz- ene (14.25 mg) was
heated in a TGA boat from room temperature to 1000.degree. C. at
10.degree. C./min under a nitrogen atmosphere, resulting in a char
yield of 65%. Polymerization to a thermoset occurred by heating the
sample from 200 to 500.degree. C. Further heating to 1000.degree.
C. resulted in carbonization and the formation of a carbon
nanotube-iron nanoparticle composition. Raman and x-ray diffraction
studies confirmed the formation of carbon nanotubes and Fe
nanoparticles in the carbonization bulk composition.
EXAMPLE 44
[0128] Carbon nanotube formation from
1-(ferrocenylethynyl)-3-(phenylethyn- yl)benzene polymer
composition--The thermoset from the polymerization of
1-(ferrocenylethynyl)-3-(phenylethynyl)benzene (13.3 mg) using the
procedure in Example 25 was further heated in the TGA boat from 30
to 1000.degree. C. at 10.degree. C./min under a nitrogen
atmosphere, resulting in a char yield of 86%. The thermoset lost 9%
of its weight between 400 and 600.degree. C. The remaining 5%
occurred between 600 and 1000.degree. C., resulting in carbon
nanotube and iron nanoparticle formation. Raman and x-ray
diffraction studies show the formation of carbon nanotubes and Fe
nanoparticles in the carbonization bulk composition. The x-ray
diffraction study showed the four characteristic reflection [(111),
(220), (222), and (422)] values for carbon nanotubes. The x-ray
(111) reflection value was 25.95.
EXAMPLE 45
[0129] Formation of carbon nanotube fibers from
1-(ferrocenylethynyl)-3-(p-
henylethynyl)benzene--1-(Ferrocenylethynyl)-3-(phenylethynyl)benzene
(0.1 g) prepared as in Example 3 was weighed into a test tube,
wrapped with heating tape, and melted by heating at 275-300.degree.
C. resulting in an increase in viscosity. Before gelation or
solidification occurred, a glass rod was pushed into the thick
composition and removed resulting in the formation of a fibrous
glassy material. While continuing to heat, the fibrous material
solidified. At this time, the fibrous material was removed, placed
on a graphitic plate in a tube furnace, and heated at 1.degree.
C./min to 1000.degree. C. The fibrous sample was cooled at
0.5.degree. C./min to room temperature. Raman and x-ray studies
showed the formation of carbon nanotubes along with Fe
nanoparticles. These results indicate that carbon
nanotube-containing fibers can be formed from precursor material
containing iron by thermally curing to a shaped fiber, and further
heat-treating at elevated temperatures resulting in the formation
of carbon nanotube-containing fibers with magnetic properties.
EXAMPLE 46
[0130] Carbon nanotube formation from
1-(ferrocenylethynyl)-3-(phenylethyn- yl)benzene by direct
conversion to thermoset and carbon nanotube-iron nanoparticle
composition--1-(Ferrocenylethynyl)-3-(phenylethynyl)benzene (15.4
mg) prepared as in Example 3 was weighed into a TGA boat heated
under a nitrogen atmosphere at 225.degree. C. for 60 min resulting
in a weight loss of 10% due to solvent and other volatiles. Upon
cooling back to room temperature, the sample was then carbonized by
heating to 1000.degree. C. at 10.degree. C./min under a nitrogen
atmosphere, resulting in a char yield of 88%. Raman and x-ray
diffraction studies show the formation of carbon nanotubes and Fe
nanoparticles in the carbonization bulk composition.
EXAMPLE 47
[0131] Carbon nanotube formation from
1-(ferrocenylethynyl)-4-(phenylethyn- yl)benzene polymer
composition--The resulting thermoset from the polymerization of
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene (11.4 mg) using the
procedure in Example 27 was further heated in a TGA boat from 30 to
1000.degree. C. at 10.degree. C./min under a nitrogen atmosphere,
resulting in a char yield of 84%. The thermoset lost 10% of its
weight between 400 and 600.degree. C. The remaining 6% occurred
between 600 and 1000.degree. C., resulting in carbonization to
carbon nanotubes and the formation of iron nanoparticles. Raman and
x-ray diffraction studies show the formation of carbon nanotubes
and Fe nanoparticles in the carbonization bulk composition.
EXAMPLE 48
[0132] Conversion of 1-ferrocenylethynyl-4-phenylethynylbenzene to
carbon nanotube-iron nanoparticle
composition--1-Ferrocenylethynyl-4-phenylethyn- ylbenzene (10.81
mg) prepared as in Example 4 was weighed in a TGA pan, placed into
a TGA/DTA chamber, and heated at 10.degree. C. under a nitrogen
atmosphere from room temperature to 1000.degree. C. resulting in a
char yield of 85%. The carbon nanotube-iron nanoparticle carbon
composition was attracted to a bar (permanent) magnet, indicating
ferromagnetic behavior. During the DTA scan, the sample was
observed to melt at 204.degree. C. and to show an exotherm at
358.degree. C. attributed to the cure to a thermoset. The x-ray
(111) was readily apparent.
EXAMPLE 49
[0133] Carbon nanotube formation from
1-(ferrocenylethynyl)-4-(phenylethyn- yl)benzene by direct
conversion to thermoset followed by carbon nanotube-iron
nanoparticle bulk composition--1-(Ferrocenylethynyl)-4-(phe-
nylethynyl)benzene (20.4 mg) prepared as in Example 4 was weighed
into a TGA boat and heated under a nitrogen atmosphere at
225.degree. C. for 60 min resulting in a weight loss of 12% due to
solvent and other volatiles. Upon cooling back to room temperature,
the sample was then carbonized by heating to 1000.degree. C. at
10.degree. C./min under a nitrogen atmosphere, resulting in a char
yield of 85% and the formation of carbon nanotubes and iron
nanoparticles. Raman and x-ray diffraction studies show the
formation of carbon nanotubes and Fe nanoparticles in the
carbonization bulk composition. The x-ray (111) reflection value
was 25.99.
EXAMPLE 50
[0134] Conversion of
bis(ferrocenylethynyl)-bis(triethylphosphine)palladiu- m to carbon
nanotubes--A sample (38.60 mg) of bis(ferrocenylethynyl)-bis(t-
riethylphosphine)palladium was heated at 10.degree. C./min to
1400.degree. C. resulting in a weight retention (char yield) of
50%. Raman (characteristic pattern) and x-ray studies confirmed the
presence of carbon nanotubes in the carbon nanotube-metal
nanoparticle carbon composition. The characteristic x-ray (111),
(220), (222), and (422) reflections for carbon nanotubes were
readily apparent along with the Fe--Pd nanoparticle phase.
[0135] B. Formation of Carbon Nanotube Composition from a
Metallocenyl Compound and an Ethynyl Compound
EXAMPLE 51
[0136] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and 1,2,4-tris(phenylethynyl)benzene
to carbon nanotube-iron nanoparticle carbon composition--A mixture
prepared from 9.5 mg (0.0227 mmol) of 1,4-bis(ferrocenyl)butadiyne
and 8.6 mg (0.0229 mmol) of 1,2,4-tris(phenylethynyl)benzene was
ground with a mortar & pestle and thoroughly mixed. A sample
(13.35 mg) of the mixture was placed on a sample holder of a TGA
system and heated at 10.degree. C. under a nitrogen atmosphere from
room temperature to 1000.degree. C. resulting in a char yield of
78% and the formation of a carbon nanotube-iron nanoparticle
composition. Raman and x-ray studies confirmed the presence of
carbon nanotubes in the carbon composition. The Raman spectrum
showed the characteristic D and G lines and strong absorption at
2400-3250 cm.sup.-1 attributed to carbon nanotubes. The x-ray
diffraction study showed the four characteristic reflection [(111),
(220), (222), and (422)] values for carbon nanotubes along with the
reflection pattern for bcc iron nanoparticles. The x-ray (111)
reflection for carbon nanotubes was readily apparent.
EXAMPLE 52
[0137] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and 1,3,5-tris(phenylethynyl)benzene
to carbon nanotube-iron nanoparticle carbon composition--A mixture
prepared from 8.7 mg (0.0208 mmol) of 1,4-bis(ferrocenyl)butadiyne
and 7.9 mg (0.0209 mmol) of 1,3,5-tris(phenylethynyl)benzene was
ground with a mortar & pestle and thoroughly mixed. A sample
(13.25 mg) of the mixture was placed on a sample holder of a TGA
system and heated at 10.degree. C. under a nitrogen atmosphere from
room temperature to 1000.degree. C. resulting in a char yield of
81% and the formation of a carbon nanotube-iron nanoparticle
composition. Raman and x-ray studies confirmed the presence of
carbon nanotubes in the carbon composition. The Raman spectrum
showed the characteristic D and G lines and strong absorption at
2400-3250 cm.sup.-1 attributed to carbon nanotubes. The x-ray
diffraction study showed the four characteristic reflection [(111),
(220), (222), and (422)] values for carbon nanotubes along with the
reflection pattern for iron bcc nanoparticles. The x-ray (111)
reflection for carbon nanotubes was readily apparent.
EXAMPLE 53
[0138] Heat-treatment of 10/90 weight percent mixture of
1,4-bis(ferrocenyl)butadiyne and 1,3,5-tris(phenylethynyl)benzene
and conversion into carbon nanotubes--A sample (15.6 mg) of 10/90
mixture was weighed into a TGA boat and heated at 10.degree. C./min
to 1000.degree. C. resulting in a char yield of 74%. Raman and
x-ray diffraction studies showed the presence of carbon nanotubes
and iron nanoparticles in the carbon composition. Carbon nanotubes
have four characteristic reflections [(111), (220), (222), and
(420)]. The x-ray (111) was readily apparent. The nanoparticles
attributed to iron have reflections in the same vicinity as the
other reflections for the carbon nanotubes.
EXAMPLE 54
[0139] Conversion of 75/25 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon composition--A mixture prepared from 15.0 mg
(0.0359 mmol) of 1,4-bis(ferrocenyl)butadiyne and 5.7 mg (0.0120
mmol) of 1,2,4,5-tetrakis(phenylethynyl)benzene was ground with a
mortar & pestle and thoroughly mixed. A sample (16.05 mg) of
the mixture was placed on a sample holder of a TGA/DTA system and
heated at 10.degree. C. under a nitrogen atmosphere from room
temperature to 1000.degree. C. resulting in a char yield of 79% and
the formation of carbon nanotubes. Raman and x-ray diffraction
studies confirmed the presence of carbon nanotubes-iron
nanoparticles in the carbon composition.
EXAMPLE 55
[0140] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle composition by heating at 500.degree. C. for 1 hour--A
50/50 molar mixture (15.93 mg) of 1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 500.degree. C. and
held at 500.degree. C. for 1 hour resulting in the formation of a
carbon nanotube-iron nanoparticle composition. Raman and x-ray
studies confirmed the presence of carbon nanotubes in the carbon
composition. The Raman spectrum showed the characteristic D and G
lines and strong absorption at 2400-3250 cm-1 attributed to carbon
nanotubes. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes along with the reflection pattern for bcc iron
nanoparticles. The x-ray (111) reflection for carbon nanotubes was
readily apparent.
EXAMPLE 56
[0141] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle composition by heating at 500.degree. C. for 4 hour--A
50/50 molar mixture (.about.50 mg) of 1,4-bis(ferrocenyl)butadiyne
and 1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 500.degree. C. and
held at 500.degree. C. for 4 hours. Raman and x-ray studies
confirmed the presence of carbon nanotubes in the carbon
composition. The Raman spectrum showed the characteristic D and G
lines and strong absorption at 2400-3250 cm.sup.-1 attributed to
carbon nanotubes. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for bcc iron nanoparticles.
The x-ray (111) reflection for carbon nanotubes was readily
apparent. The carbon nanotube-iron nanoparticle composition was
attracted to a bar (permanent) magnet, indicating ferromagnetic
behavior.
EXAMPLE 57
[0142] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
composition by heating at 600.degree. C. for 1 hour--A 50/50 molar
mixture (15.66 mg) of 1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 600.degree. C. and
held at 600.degree. C. for 1 hour resulting in the formation of a
carbon nanotube-iron nanoparticle composition. Raman and x-ray
studies confirmed the presence of carbon nanotubes in the carbon
composition. The Raman spectrum showed the characteristic D and G
lines and strong absorption at 2400-3250 cm.sup.-1 attributed to
carbon nanotubes. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for bcc iron nanoparticles.
The x-ray (111) reflection for carbon nanotubes was readily
apparent. The carbon nanotube-iron nanoparticle composition
retained 89% of the original weight and was attracted to a bar
(permanent) magnet, indicating ferromagnetic behavior.
EXAMPLE 58
[0143] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon composition by heating at 600.degree. C. for 4
hour--A 50/50 molar mixture (.about.50 mg) of
1,4-bis(ferrocenyl)butadiyn- e and
1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 600.degree. C. and
held at 600.degree. C. for 4 hours. Raman and x-ray studies
confirmed the presence of carbon nanotubes in the carbon
composition. The Raman spectrum showed the characteristic D and G
lines and strong absorption at 2400-3250 cm.sup.-1 attributed to
carbon nanotubes. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for bcc iron nanoparticles.
The x-ray (111) reflection for carbon nanotubes was readily
apparent. The carbon nanotube-iron nanoparticle was attracted to a
bar (permanent) magnet, indicating ferromagnetic behavior.
EXAMPLE 59
[0144] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle composition by heating at 700.degree. C. for 1 hour--A
50/50 molar mixture (15.93 mg) of 1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 700.degree. C. and
held at 700.degree. C. for 1 hour resulting in the retention of 87%
of the original weight. Raman and x-ray studies confirmed the
presence of carbon nanotubes in the carbon composition. The Raman
spectrum showed the characteristic D and G lines and strong
absorption at 2400-3250 cm.sup.-1 attributed to carbon nanotubes.
The x-ray diffraction study showed the, four characteristic
reflection [(111), (220), (222), and (422)] values for carbon
nanotubes and the pattern for bcc iron nanoparticles. The x-ray
(111) reflection for carbon nanotubes was readily apparent. The
lattice parameter for carbon nanotubes was 5.9395 .ANG.. The
average size of carbon nanotubes was 4.9 nm. The carbon
nanotube-iron nanoparticle was attracted to a bar (permanent)
magnet, indicating ferromagnetic behavior.
EXAMPLE 60
[0145] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon by heating at 800.degree. C. for 1 hour--A
50/50 molar mixture (13.24 mg) of 1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 800.degree. C. and
held at 800.degree. C. for 1 hour resulting in a retention of 87%
of the original weight. Raman and x-ray studies confirmed the
presence of carbon nanotubes in the carbon composition. The Raman
spectrum showed the characteristic D and G lines and strong
absorption at 2400-3250 cm.sup.-1 attributed to carbon nanotubes.
The x-ray diffraction study showed the four characteristic
reflection [(111), (220), (222), and (422)] values for carbon
nanotubes and the pattern for bcc iron nanoparticles. The x-ray
(111) reflection for carbon nanotubes was readily apparent. The
carbon nanotube-iron nanoparticle was attracted to a bar
(permanent) magnet, indicating ferromagnetic behavior.
EXAMPLE 61
[0146] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle composition by heating at 800.degree. C. for 4 hour--A
50/50 molar mixture (.about.50 mg) of 1,4-bis(ferrocenyl)butadiyne
and 1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 800.degree. C. and
held at 800.degree. C. for 4 hours. Raman and x-ray studies
confirmed the presence of carbon nanotubes in the carbon
composition. The Raman spectrum showed the characteristic D and G
lines and strong absorption at 2400-3250 cm.sup.-1 attributed to
carbon nanotubes. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for bcc iron nanoparticles.
The x-ray (111) reflection for carbon nanotubes was readily
apparent. The carbon nanotube-iron nanoparticle was attracted to a
bar (permanent) magnet, indicating ferromagnetic behavior.
EXAMPLE 62
[0147] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle composition by heating at 1000.degree. C. for 4
hour--A 50/50 molar mixture (.about.50 mg) of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 1000.degree. C. and
held at 1000.degree. C. for 4 hours. Raman and x-ray studies
confirmed the presence of carbon nanotubes in the carbon
composition. The Raman spectrum showed the characteristic D and G
lines and strong absorption at 2400-3250 cm.sup.-1 attributed to
carbon nanotubes. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for bcc iron nanoparticles.
The carbon nanotube-iron nanoparticle carbon composition was
attracted to a bar (permanent) magnet, indicating ferromagnetic
behavior.
EXAMPLE 63
[0148] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle composition by heating to 1000.degree. C.--A 50/50
molar mixture (.about.50 mg) of 1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene was placed in a platinum
sample holder of a TGA system and heated at 10.degree. C. under a
nitrogen atmosphere from room temperature to 1000.degree. C. and
quickly cooled back to room temperature. Raman and x-ray studies
confirmed the presence of carbon nanotubes in the carbon
composition. The Raman spectrum showed the characteristic D and G
lines and strong absorption at 2400-3250 cm.sup.-1 attributed to
carbon nanotubes. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for bcc iron nanoparticles.
The x-ray (111) reflection for carbon nanotubes was readily
apparent. The carbon nanotube-iron nanoparticle was attracted to a
bar (permanent) magnet, indicating ferromagnetic behavior.
EXAMPLE 64
[0149] Formation of carbon nanotube-containing fibers from 50/50
molar mixture of 1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethyny- l)benzene--A mixture (0.1 g)
prepared from 0.05 g of 1,4-bis(ferrocenyl)butadiyne and 0.05 g of
1,2,4,5-tetrakis(phenylethynyl- )benzene was ground with a mortar
& pestle and thoroughly mixed. The mixture was added to a test
tube, wrapped with heating tape, and melted by heating at
275-300.degree. C. resulting in an increase in viscosity. Before
gelation or solidification occurred, a glass rod was pushed into
the thick composition and removed resulting in the formation of a
fibrous glassy material. While continuing to heat, the fibrous
material solidified. At this time, the fibrous material was
removed, placed on a graphitic plate in a tube furnace, and heated
at 1.degree. C./min to 1000.degree. C. The fibrous sample was
cooled at 0.5.degree. C./min to room temperature. Raman and x-ray
studies showed the formation of carbon nanotubes along with Fe
nanoparticles. X-ray diffraction study showed the formation of the
(111) reflection for carbon nanotubes. These results indicate that
carbon nanotube-containing fibers can be formed from precursor
material containing iron by thermally curing to a shaped fiber, and
further heat-treatment at elevated temperatures resulting in the
formation of carbon nanotube-containing fibers with magnetic
properties.
EXAMPLE 65
[0150] Conversion of 50/50 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon composition--A mixture prepared from 8.7 mg
(0.0208 mmol) of 1,4-bis(ferrocenyl)butadiyne and 10.0 mg (0.0209
mmol) of 1,2,4,5-tetrakis(phenylethynyl)benzene was ground with a
mortar & pestle and thoroughly mixed. A sample (15.25 mg) of
the mixture was placed on a sample holder of a TGA/DTA system and
heated at 10.degree. C. under a nitrogen atmosphere from room
temperature to 1000.degree. C. resulting in a char yield of 86%.
Raman and x-ray studies confirmed the presence of carbon
nanotube-iron nanoparticle carbon composition. The lattice
parameter for carbon nanotubes was 5.9629 .ANG.. The average size
of carbon nanotubes was 5.0 nm. The carbon nanotube-iron
nanoparticle carbon composition was attracted to a bar (permanent)
magnet, indicating ferromagnetic behavior. The average size of Fe
bcc nanoparticles was 15.2 nm.
EXAMPLE 66
[0151] Conversion of 75/25 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon composition--A mixture prepared from 15.0 mg
(0.0359 mmol) of 1,4-bis(ferrocenyl)butadiyne and 5.7 mg (0.0120
mmol) of 1,2,4,5-tetrakis(phenylethynyl)benzene was ground with
mortar & pestle and thoroughly mixed. A sample (18.97 mg) of
the mixture was placed on a sample holder of a TGA/DTA system and
heated at 10.degree. C. under a nitrogen atmosphere from room
temperature to 1000.degree. C. resulting in a char yield of 87% and
the formation of a carbon nanotube-iron nanoparticle composition.
Raman and x-ray studies confirmed the presence of carbon nanotubes
in the carbon composition. The Raman spectrum showed the
characteristic D and G lines and strong absorption at 2400-3250
cm.sup.-1 attributed to carbon nanotubes. The x-ray diffraction
study showed the four characteristic reflection [(111), (220),
(222), and (422)] values for carbon nanotubes along with the
reflection pattern for iron bcc nanoparticles. The x-ray (111)
reflection for carbon nanotubes was readily apparent.
EXAMPLE 67
[0152] Conversion of 10/90 molar mixture of
1,4-bis(ferrocenyl)butadiyne and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon composition--A mixture prepared from 1.9 mg
(0.0045 mmol) of 1,4-bis(ferrocenyl)butadiyne and 20.0 mg (0.0418
mmol) of 1,2,4,5-tetrakis(phenylethynyl)benzene was ground with a
mortar & pestle and thoroughly mixed. A sample (18.97 mg) of
the mixture was placed on a sample holder of a TGA/DTA system and
heated at 10.degree. C. under a nitrogen atmosphere from room
temperature to 1000.degree. C. resulting in a char yield of 84% and
the formation of a carbon nanotube-iron nanoparticle composition.
Raman and x-ray studies confirmed the presence of carbon nanotubes
in the carbon composition. The Raman spectrum showed the
characteristic D and G lines and strong absorption at 2400-3250
cm.sup.-1 attributed to carbon nanotubes. The x-ray diffraction
study showed the four characteristic reflection [(111), (220),
(222), and (422)] values for carbon nanotubes along with the
reflection pattern for iron bcc nanoparticles. The x-ray (111)
reflection for carbon nanotubes was readily apparent.
EXAMPLE 68
[0153] Pyrolysis of sample prepared from 1/100 molar mixture of
bis(ferrocenyl)-butadyine/1,2,4,5-tetrakis(phenylethynyl)benzene
heated to 1000.degree. C. and formation of carbon
nanotubes--Bis(ferrocenyl)buta- diyne (0.91 mg, 0.0021 mmol) and
1,2,4,5-tetrakis(phenylethynyl)benzene (99 mg, 0.21 mmol) were
thoroughly mixed, degassed at 225.degree. C. (15 min), and used for
pyrolysis studies. A sample (30.86 mg) of the 1/100 molar mixture
was heated at 10.degree. C./min to 1000.degree. C. under an inert
atmosphere resulting in a weight retention of 84%. Raman and x-ray
studies confirmed the presence of carbon nanotubes in the carbon
nanotube-iron nanoparticle carbon composition. The characteristic
x-ray (111), (220), (222), and (422) reflections for carbon
nanotubes were readily apparent, whereas the bcc iron nanoparticle
pattern was not evident. X-ray diffraction study showed the
characteristic (111) reflection value at about 25.85 (2-Theta). The
lattice parameter for carbon nanotube was 5.9767 .ANG.. The average
size of carbon nanotubes was 3.82 nm.
EXAMPLE 69
[0154] Conversion of 50/50 molar mixture of
1,3-bis(ferrocenylethynyl)benz- ene and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon composition--A mixture prepared from 10.0 mg
(0.0202 mmol) of 1,3-bis(ferrocenylethynyl)benzene prepared as in
Example 1 and 9.7 mg (0.0203 mmol) of
1,2,4,5-tetrakis(phenylethynyl)benzene was ground with a mortar
& pestle and thoroughly mixed. A sample (15.82 mg) of the
mixture was placed on a sample holder of a TGA/DTA system and
heated at 10.degree. C. under a nitrogen atmosphere from room
temperature to 1000.degree. C. resulting in a char yield of 84% and
the formation of a carbon nanotube-iron nanoparticle composition.
Raman and x-ray studies confirmed the presence of carbon nanotubes
in the carbon composition. The Raman spectrum showed the
characteristic D and G lines and strong absorption at 2400-3250
cm.sup.-1 attributed to carbon nanotubes. The x-ray diffraction
study showed the four characteristic reflection [(111), (220),
(222), and (422)] values for carbon nanotubes along with the
reflection pattern for bcc iron nanoparticles. The x-ray (111)
reflection for carbon nanotubes was readily apparent.
EXAMPLE 70
[0155] Conversion of 75/25 molar mixture of
1-ferrocenylethynyl-4-phenylet- hynylbenzene and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon composition--A mixture prepared from 15.0 mg
(0.0389 mmol) of 1-ferrocenylethynyl-4-phenylethynylbenzene
prepared as in Example 4 and 6.2 mg (0.0130 mmol) of
1,2,4,5-tetrakis(phenylethynyl)benzene was ground with a mortar
& pestle and thoroughly mixed. A sample (18.04 mg) of the
mixture was placed on a sample holder of a TGA/DTA system and
heated at 10.degree. C. under a nitrogen atmosphere from room
temperature to 1000.degree. C. resulting in a char yield of 90% and
the formation of a carbon nanotube-iron nanoparticle composition.
Raman and x-ray studies confirmed the presence of carbon nanotubes
in the carbon composition. The Raman spectrum showed the
characteristic D and G lines and strong absorption at 2400-3250
cm.sup.-1 attributed to carbon nanotubes. The x-ray diffraction
study showed the four characteristic reflection [(111), (220),
(222), and (422)] values for carbon nanotubes along with the
reflection pattern for bcc iron nanoparticles. The x-ray (111)
reflection for carbon nanotubes was readily apparent.
EXAMPLE 71
[0156] Conversion of 50/50 molar mixture of
1-ferrocenylethynyl-4-phenylet- hynylbenzene and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon composition--A mixture prepared from 10.1 mg
(0.0262 mmol) of 1-ferrocenylethynyl-4-phenylethynylbenzene
prepared as in Example 4 and 20.0 mg (0.0259 mmol) of
1,2,4,5-tetrakis(phenylethynyl)benzene was ground with a mortar
& pestle and thoroughly mixed. A sample (18.04 mg) of the
mixture was placed on a sample holder of a TGA/DTA system and
heated at 10.degree. C. under a nitrogen atmosphere from room
temperature to 1000.degree. C. resulting in a char yield of 85% and
the formation of a carbon nanotube-iron nanoparticle composition.
Raman and x-ray studies confirmed the presence of carbon nanotubes
in the carbon composition. The Raman spectrum showed the
characteristic D and G lines and strong absorption at 2400-3250
cm.sup.-1 attributed to carbon nanotubes. The x-ray diffraction
study showed the four characteristic reflection [(111), (220),
(222), and (422)] values for carbon nanotubes along with the
reflection pattern for bcc iron nanoparticle. The x-ray (111)
reflection for carbon nanotubes was readily apparent.
EXAMPLE 72
[0157] Conversion of 25/75 molar mixture of
1-ferrocenylethynyl-4-phenylet- hynylbenzene and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-iron
nanoparticle carbon composition--A mixture prepared from 5.0 mg
(0.0130 mmol) of 1-ferrocenylethynyl-4-phenylethynylbenzene
prepared as in Example 4 and 18.5 mg (0.0388 mmol) of
1,2,4,5-tetrakis(phenylethynyl)benzene was ground with a mortar
& pestle and thoroughly mixed. A sample (14.07 mg) of the
mixture was placed on a sample holder of a TGA/DTA system and
heated at 10.degree. C. under a nitrogen atmosphere from room
temperature to 1000.degree. C. resulting in a char yield of 84% and
the formation of a carbon nanotube-iron nanoparticle composition.
Raman and x-ray studies confirmed the presence of carbon nanotubes
in the carbon composition. The Raman spectrum showed the
characteristic D and G lines and strong absorption at 2400-3250
cm.sup.-1 attributed to carbon nanotubes. The x-ray diffraction
study showed the four characteristic reflection [(111), (220),
(222), and (422)] values for carbon nanotubes along with the
reflection pattern for bcc iron nanoparticles. The x-ray (111)
reflection for carbon nanotubes was readily apparent.
EXAMPLE 73
[0158] Conversion of 1/15 molar mixture of
bis(ferrocenylethynyl)-bis(trip- henylphosphine)nickel and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotubes--A
mixture containing bis(ferrocenylethynyl)-bis(triphenylphosp-
hine)nickel (7 mg, 0.0070 mmol) prepared as in Example 5 and
1,2,4,5-tetrakis(phenylethynyl)benzene (50 mg, 0.105 mmol) was
prepared and mixed. The sample was added to an aluminum planchet,
heated to melt at 250.degree. C., and degassed for 5 minutes at
reduced pressure. A sample (22.97 mg) was loaded onto a Pt TGA pan,
heated at 250.degree. C., and then heated at 10.degree. C./min to
1000.degree. C. Raman and x-ray diffraction studies showed the
formation of carbon nanotubes.
EXAMPLE 74
[0159] Conversion of 1/15 molar mixture of
bis(ferrocenylethynyl)-bis(trip- henylphosphine)nickel and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-metal
nanoparticle composition--Bis(ferrocenylethynyl)-bis(triph-
enylphosphine)nickel (0.014 g. 0.014 mmol) prepared as in Example 5
and 1,2,4,5-tetrakis(phenylethynyl)benzene (0.10 g, 0.21 mmol) were
added to an Al planchet, heated to melt at 225.degree. C. for 10
min at reduced pressure, and then quickly cooled. A sample (22.97
mg) of resulting mixture was loaded onto Pt TGA pan and heated at
10.degree. C./min to 1000.degree. C. yielding a weight retention of
63%. Raman and x-ray diffraction studies showed the characteristic
patterns for carbon nanotube formation. X-ray diffraction also
showed Fe--Ni nanoparticles (15 nm in size) in the fcc form.
[0160] C. Formation of Carbon Nanotube Composition from a
Metallocenyl Compound and a Metal-Ethynyl Complex
EXAMPLE 75
[0161] Polymerization and conversion of 50/50 molar mixture of 1:1
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene to carbon
nanotube-iron/cobalt alloy nanoparticle carbon composition--A
mixture prepared from 11.15 mg (0.0289 mmol) of
1-(ferrocenylethynyl)-4-(phenylet- hynyl)benzene prepared as in
Example 4 and 22.07 mg (0.0289 mmol) of 1:1 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in
Example 7 was ground with a mortar & pestle and thoroughly
mixed. A sample (21.01 mg) of the mixture was placed on a sample
holder of a TGA system and heated at 10.degree. C. under a nitrogen
atmosphere from room temperature to 1000.degree. C. resulting in a
char yield of 75%. Raman and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-iron/cobalt alloy
nanoparticle carbon composition. The x-ray diffraction study showed
the four characteristic reflection [(111), (220), (222), and (422)]
values for carbon nanotubes and the pattern for bcc cobalt
nanoparticles. The x-ray (111) reflection for carbon nanotubes was
readily apparent. Raman and x-ray studies confirmed the presence of
carbon nanotubes-bcc cobalt nanoparticles in the carbon
composition.
EXAMPLE 76
[0162] Heat-treatment of 1:1 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1-(ferrocenyl)-4-(phenylethyny- l)benzene at 600.degree. C. for 4
hr--1:1 Hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (10.2 mg, 0.013 mmol)
prepared as in Example 7 and
1-(ferrocenyl)-4-(phenylethynyl)benzene (6.6 mg, 0.017 mmol)
prepared as in Example 4 were thoroughly mixed and heated at
10.degree. C./min to 600.degree. C. and isothermed for 4 hr under a
nitrogen atmosphere in a platinum TGA cup using a TGA/DTA analyzer.
After the heat-treatment at 600.degree. C., the sample showed a
weight retention of 49%. The sample showed magnetic properties as
determined by its attraction to a bar magnet. X-ray diffraction
study showed the formation of very small carbon
nanoparticles-carbon nanotubes-cobalt nanoparticle in the carbon
composition. X-ray diffraction studies showed the formation of
cobalt in the cobalt-iron nanoparticle alloy in the bcc phase.
EXAMPLE 77
[0163] Polymerization and conversion of 90/10 molar mixture of 1:1
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene to carbon
nanotube-iron/cobalt alloy nanoparticle carbon composition--A
mixture prepared from 0.772 mg (0.0020 mmol) of
1-(ferrocenylethynyl)-4-(phenylet- hynyl)benzene prepared as in
Example 4 and 15.25 mg (0.0199 mmol) of 1:1 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in
Example 7 was ground with a mortar & pestle and thoroughly
mixed. A sample (11.25 mg) of the mixture was placed on a sample
holder of a TGA system and heated at 10.degree. C. under a nitrogen
atmosphere from room temperature to 1000.degree. C. resulting in a
char yield of 70%. Raman and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-iron/cobalt alloy
nanoparticle carbon composition. The x-ray diffraction study showed
the four characteristic reflection [(111), (220), (222), and (422)]
values for carbon nanotubes and the pattern for fcc cobalt
nanoparticles. The x-ray (111) reflection for carbon nanotubes was
readily apparent. Raman and x-ray studies confirmed the presence of
carbon nanotubes-bcc cobalt nanoparticles in the carbon
composition.
[0164] D. Formation of Carbon Nanotube Composition from a
Metal-Ethynyl Complex
EXAMPLE 78
[0165] Pyrolysis of 1:1 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and conversion to carbon
nanotubes-cobalt nanoparticle composition--1:1 Hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene (10.0 mg, 13.1
mmol) prepared as in Example 7 was thoroughly mixed and heated at
10.degree. C./min to 1000.degree. C. in a nitrogen atmosphere in a
platinum TGA cup using a TGA/DTA analyzer. The sample exhibited an
endotherm at 197.degree. C. (m.p.), an exotherm at about
190.degree. C. attributed to the reaction of the ethynyl groups to
a thermoset, and another exotherm at =843.degree. C. Raman and
x-ray studies confirmed the presence of carbon nanotubes in the
carbon nanotube-cobalt nanoparticle carbon composition. The x-ray
diffraction study showed the four characteristic reflection [(111),
(220), (222), and (422)] values for carbon nanotubes and the
pattern for fcc cobalt nanoparticles. The x-ray (111) reflection
for carbon nanotubes was readily apparent. At 1000.degree. C., the
sample showed a char yield of 83%.
EXAMPLE 79
[0166] Polymerization and conversion of 1:1 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene to carbon
nanoparticle-cobalt nanoparticle composition--1:1
Hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (9.50 mg) prepared as in
Example 7 was heated at 10.degree. C./min to 600.degree. C. The
sample was heated at 600.degree. C. for 4 hr. After the
heat-treatment at 600.degree. C., the sample showed a weight
retention of 58%. During the heat-treatment, polymerization through
the alkyne groups to a shaped composition occurred during the early
part of the heating process. Moreover, decomposition
(200-500.degree. C.) of the cobalt complex was also occurring
during the heat-treatment resulting in the formation of cobalt
nanoparticle polymer composition. Above 500.degree. C., the
composition was converted into a very small carbon
nanoparticle-cobalt nanoparticle carbon composition.
EXAMPLE 80
[0167] Conversion of 1:3 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C. to
carbon nanotube-cobalt nanoparticle composition--A sample (21.14
mg) of 1:3 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzen- e prepared as in Example 8
was heated at 10.degree. C./min to 1000.degree. C. resulting in a
char yield of 78%. Raman and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-cobalt nanoparticle
carbon composition. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for fcc cobalt nanoparticles.
The x-ray (111) reflection for carbon nanotubes was readily
apparent.
EXAMPLE 81
[0168] Pyrolysis of 1:10 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated at 700.degree. C. for
4 hr--A sample (18.43 mg) of 1:10 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 9 was
heated at 30.degree. C./min to 250.degree. C. (30 min), ramped at
10.degree. C./min to 700.degree. C., and held for 4 hr under an
inert atmosphere resulting in a weight retention of 42%. Raman and
x-ray studies confirmed a very small carbon nanoparticle-carbon
nanotube-cobalt nanoparticle carbon composition.
EXAMPLE 82
[0169] Conversion of 1:10 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C. to
carbon nanotube-cobalt nanoparticle composition--A sample (18.43
mg) of 1:10 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benze- ne prepared as in Example 9
was heated at 10.degree. C./min to 1000.degree. C. resulting in a
char yield of 77%. Raman and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-cobalt nanoparticle
carbon composition. Raman and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-cobalt nanoparticle
carbon composition. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for fcc cobalt nanoparticles.
The x-ray (111) reflection for carbon nanotubes was readily
apparent.
EXAMPLE 83
[0170] Pyrolysis of 1:15 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated at 700.degree. C. for
4 hr--A sample (23.04 mg) of 1:15 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 10
was heated at 30.degree. C./min to 250.degree. C. (30 min), ramped
at 10.degree. C./min to 700.degree. C., and held for 4 hr under an
inert atmosphere resulting in a weight retention of 64%. X-ray
diffraction study showed the formation of very small carbon
nanoparticles-carbon nanotubes-cobalt nanoparticles in the carbon
composition.
EXAMPLE 84
[0171] Conversion of 1:15 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated at 900.degree. C. for
4 hr to carbon nanotube-cobalt nanoparticle composition--A sample
(25.49 mg) of 1:15 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)be- nzene prepared as in Example 10
was heated at 30.degree. C./min to 250.degree. C. (30 min), ramped
at 10.degree. C./min to 900.degree. C., and held for 4 hr under an
inert atmosphere resulting in a weight retention of 44%. Raman and
x-ray studies confirmed the presence of carbon nanotubes in the
carbon nanotube-cobalt nanoparticle carbon composition. The x-ray
(111), (220), (222), and (422) reflections for carbon nanotubes
were readily apparent, whereas the presence of cobalt nanoparticles
in the fcc phase was weakly observed.
EXAMPLE 85
[0172] Conversion of 1:15 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C.--A
sample (22.51 mg) of 1:15 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 10
was heated at 10.degree. C./min to 1000.degree. C. under an inert
atmosphere resulting in a weight retention of 87%. Raman and x-ray
studies confirmed the presence of carbon nanotubes in the carbon
nanotube-cobalt nanoparticle carbon composition. The x-ray (111),
(220), (222), and (422) reflections for carbon nanotubes were
readily apparent, whereas the presence of cobalt nanoparticles in
the fcc phase was weak. Moreover, it appeared that the cobalt was
somehow reacting with the carbon domain since evidence of free
cobalt in the fcc phase was weakly observed.
EXAMPLE 86
[0173] Pyrolysis of 1:15 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C. on
silica wafer and formation of carbon nanotubes and thin film
containing carbon nanotubes on the surface of silica--A sample (9.0
mg) of 1:15 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 10
was placed on a silica wafer. The silica wafer/sample was placed in
a furnace and quickly heated under an argon atmosphere to
225.degree. C. and held for 15 minutes. At this time, the
wafer/sample was slowly heated at 0.5.degree. C./min to
1000.degree. C. and then cooled at 0.4.degree. C./min to
125.degree. C. and then to room temperature overnight. Upon removal
from the, furnace, the sample easily debonded from the silica
surface. HRSEM studies on the silica surface where the sample was
heat-treated showed a thin film or presence of carbon nanotubes.
Thus, the Co nanoparticles contributed to the formation of carbon
nanotubes on the surface of the silica wafer and were embedded in
the carbon-carbon nanotube composition. X-ray diffraction study
showed the pattern reported for carbon nanotubes in the bulk sample
that detached from the silica wafer.
EXAMPLE 87
[0174] Pyrolysis of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to and at 600.degree.
C. for 4 hr--A sample (19.10 mg) of 1:20 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in
Example 1 was heated at 10.degree. C./min to 600.degree. C. and
held for 4 hr under an inert atmosphere resulting in a weight
retention of 65%. Raman and x-ray studies confirmed the presence of
small very small carbon nanoparticles and carbon nanotubes in the
carbon nanoparticle-carbon nanotube-cobalt nanoparticle carbon
composition. The x-ray (111) reflection was very broad indicating a
carbon nanotube-carbon nanoparticle composition.
EXAMPLE 88
[0175] Pyrolysis of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated at 700.degree. C.--A
sample (22.34 mg) of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 11
was heated at 10.degree. C./min to 700.degree. C. and held for 4 hr
under an inert atmosphere resulting in a weight retention of 67%.
Raman and x-ray studies confirmed the presence of very small carbon
nanoparticles-carbon nanotubes in the carbon composition. The x-ray
(111) reflection was very broad indicating a carbon nanotube-carbon
nanoparticle composition.
EXAMPLE 89
[0176] Conversion of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated at 800.degree. C. for
4 hr--A sample (24.13 mg) of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 11
was heated at 10.degree. C./min to 800.degree. C. and held for 4 hr
under an inert atmosphere resulting in a weight retention of 63%.
Raman and x-ray studies confirmed the presence of carbon nanotubes
in the carbon nanotube-cobalt nanoparticle carbon composition. The
x-ray (111), (220), (222), and (422) reflections for carbon
nanotubes were readily apparent, whereas the presence of cobalt
nanoparticles in the fcc phase was weak.
EXAMPLE 90
[0177] Conversion of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated at 900.degree. C. for
4 hr--A sample (24.73 mg) of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 11
was heated at 10.degree. C./min to 900.degree. C. and held for 4 hr
under an inert atmosphere resulting in a weight retention of 60%.
Raman and x-ray studies confirmed the presence of carbon nanotubes
in the carbon nanotube-cobalt nanoparticle carbon composition. The
x-ray (111), (220), (222), and (422) reflections for carbon
nanotubes were readily apparent, whereas the presence of cobalt
nanoparticles in the fcc phase was weak. Moreover, it appeared that
the cobalt was somehow reacting with the developing carbon-carbon
nanotube domain since evidence of free cobalt in the fcc phase was
weakly observed.
EXAMPLE 91
[0178] Conversion of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C.--A
sample (17.71 mg) of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 11
was heated at 10.degree. C./min to 1000.degree. C. under an inert
atmosphere resulting in a weight retention of 86%. Raman and x-ray
studies confirmed the presence of carbon nanotubes in the carbon
nanotube-cobalt nanoparticle carbon composition. The x-ray (111),
(220), (222), and (422) reflections for carbon nanotubes were
readily apparent, whereas the presence of cobalt nanoparticles in
the fcc phase was weak. Moreover, it appeared that the cobalt was
somehow reacting with the carbon domain since evidence of free
cobalt in the fcc phase was weakly observed.
EXAMPLE 92
[0179] Formation of carbon nanotube fibers from 1:20
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene--A sample of 1:20
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (0.1 g) prepared as in
Example 11 was weighed into a test tube, wrapped with heating tape,
and melted by heating at 275-300.degree. C. resulting in an
increase in viscosity. Before gelation or solidification occurred,
a glass rod was pushed into the thick composition and removed
resulting in the formation of a fibrous glassy material. While
continuing to heat, the fibrous material solidified. At this time,
the fibrous material was removed, placed on a graphitic plate in a
tube furnace, and heated at 1.degree. C./min to 1000.degree. C. The
fibrous sample was cooled at 0.5.degree. C./min to room
temperature. Raman and x-ray studies showed the formation of carbon
nanotubes. These results indicate that carbon nanotube-containing
fibers can be formed from precursor material containing cobalt by
thermally curing to a shaped fiber, and further heat-treatment at
elevated temperatures resulting in the formation of carbon
nanotube-containing fibers with magnetic properties.
EXAMPLE 93
[0180] Pyrolysis of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C. on
silica wafer and formation of carbon nanotubes and thin film
containing carbon nanotubes on surface of silica--A sample (9.2 mg)
of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 11
was placed on a silica wafer. The silica wafer/sample was placed in
a furnace and quickly heated under an argon atmosphere to
225.degree. C. and held for 15 minutes. At this time, the
wafer/sample was slowly heated at 0.5.degree. C./min to
1000.degree. C. and then cooled at 0.4.degree. C./min to
125.degree. C. and then to room temperature over night. Upon
removal from the furnace, the sample easily debonded from the
silica surface. HRSEM studies on the silica surface where the
sample was heat-treated showed the presence of carbon nanotubes.
Thus, the Co nanoparticles contributed to the formation of carbon
nanotubes on the surface of the silica wafer and were embedded in
the carbon-carbon nanotube composition. X-ray diffraction study
showed the characteristic reflection pattern reported for carbon
nanotubes in the bulk sample that detached from the silica
wafer.
EXAMPLE 94
[0181] Conversion of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1400.degree. C. to
carbon nanotube-cobalt nanoparticle composition--A sample (17.53
mg) of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benze- ne prepared as in Example 11
was heated at 10.degree. C./min to 1000.degree. C. under an inert
atmosphere resulting in a weight retention of 87%. Raman and x-ray
studies confirmed the presence of carbon nanotubes in the carbon
nanotube-cobalt nanoparticle carbon composition. The x-ray (111),
(220), (222), and (422) reflections for carbon nanotubes were
readily apparent, whereas the presence of cobalt nanoparticles in
the fcc phase was weak. Moreover, it appeared that the cobalt was
somehow reacting with the carbon domain since evidence of free
cobalt in the fcc phase was weakly observed.
EXAMPLE 95
[0182] Conversion of 1:20 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1570.degree. C. to
carbon nanotubes--A sample (15.48 mg) of 1:20 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in
Example 11 was heated at 10.degree. C./min to 1570.degree. C. and
held for 1 hr under an inert atmosphere resulting in a weight
retention of 84%. Raman and x-ray studies showed strong evidence of
carbon nanotubes in the carbon nanotube-cobalt nanoparticle carbon
composition. The x-ray (111), (220), (222), and (422) reflections
for carbon nanotubes were readily apparent, whereas the presence of
cobalt nanoparticles in the fcc phase was weak. Moreover, it
appeared that the cobalt was somehow reacting with the developing
carbon-carbon nanotube domain since evidence of free cobalt in the
fcc phase was weakly observed.
EXAMPLE 96
[0183] Conversion of 1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C. to
carbon nanotubes--A sample (13.65 mg) of 1:50 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in
Example 12 was heated at 10.degree. C./min to 1000.degree. C. under
an inert atmosphere resulting in a weight retention of 80%. Raman
and x-ray studies confirmed the presence of carbon nanotubes in the
carbon nanotube-cobalt nanoparticle carbon composition. The x-ray
(111), (220), (222), and (422) reflections for carbon nanotubes
were readily apparent, whereas the presence of cobalt nanoparticles
in the fcc phase was extremely weak.
EXAMPLE 97
[0184] Pyrolysis of 1:5 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and formation of carbon
nanotubes--A sample (19.06 mg) of 1:5 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 14
was heated at 30.degree. C./min to 250.degree. C. and held for 30
min. At this time, the sample was then heated at 10.degree. C./min
to 1000.degree. C. resulting in a weight retention of 74%. Raman
and x-ray studies confirmed the presence of carbon nanotubes in the
carbon nanotube-iron nanoparticle carbon composition. The x-ray
(111), (220), (222), and (422) reflections for carbon nanotubes
were readily apparent, along with the bcc iron nanoparticle pattern
and some evidence of iron carbide (Fe.sub.3C) nanoparticles. The
x-ray (111) reflection for carbon nanotubes was readily apparent.
The sample showed magnetic-properties as determined by its
attraction to a bar (permanent) magnet.
EXAMPLE 98
[0185] Heat-treatment of 1:5 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 700.degree. C. and
formation of carbon nanotubes--A sample (24.04 mg) of 1:5
hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 14
was heated at 30.degree. C./min to 250.degree. C. and held for 30
min. At this time, the sample was then heated at 10.degree. C./min
to 700.degree. C. and held at this temperature for 1 hr resulting
in a weight retention of 68%. Raman and x-ray studies confirmed the
presence of carbon nanotubes in the carbon nanotube-iron
nanoparticle carbon composition. The x-ray (111), (220), (222), and
(422) reflections for carbon nanotubes were readily apparent, along
with the bcc iron nanoparticle pattern and a small amount of iron
carbide (Fe.sub.3C) nanoparticles. The x-ray (111) reflection for
carbon nanotubes was readily apparent. The lattice parameter for
carbon nanotubes was 5.9639 .ANG.. The average size of carbon
nanotubes was 5.1 nm. The sample showed magnetic properties as
determined by its attraction to a bar (permanent) magnet. The
average size of Fe bcc nanoparticles was 12.8 nm.
EXAMPLE 99
[0186] Pyrolysis of 1:5 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C.
and formation of carbon nanotubes--A sample (19.06 mg) of 1:5
hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 14
was heated at 30.degree. C./min to 250.degree. C. and held for 30
min. At this time, the sample was then heated at 10.degree. C./min
to 1000.degree. C. resulting in a weight retention of 66%. Raman
and x-ray studies confirmed the presence of carbon nanotubes in the
carbon nanotube-iron nanoparticle carbon composition. The x-ray
(111), (220), (222), and (422) reflections for carbon nanotubes
were readily apparent, along with the bcc iron nanoparticle pattern
and a small amount of iron carbide (Fe.sub.3C) nanoparticles. The
x-ray (111) reflection for carbon nanotubes was readily apparent.
The lattice parameter for carbon nanotubes was 5.9484 .ANG.. The
average size of carbon nanotubes was 4.4 nm. The sample showed
magnetic properties as determined by its attraction to a bar
(permanent) magnet. The average size of Fe bcc nanoparticles was
7.0 nm.
EXAMPLE 100
[0187] Pyrolysis of 1:10 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C.
and formation of carbon nanotubes--A sample (33.69 mg) of 1:10
hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 15
was heated at 30.degree. C./min to 250.degree. C. and held for 30
min. At this time, the sample was then heated at 10.degree. C./min
to 1000.degree. C. resulting in a weight retention of 82%. Raman
and x-ray studies confirmed the presence of carbon nanotubes in the
carbon nanotube-iron nanoparticle carbon composition. The
characteristic x-ray (111), (220), (222), and (422) reflections for
carbon nanotubes were readily apparent, whereas the bcc iron
nanoparticle pattern was very weak. The lattice parameter for
carbon nanotubes was 5.9624 .ANG.. The average size of carbon
nanotubes was 3.9 nm. The average size of Fe nanoparticles in bcc
phase was 15.4 nm.
EXAMPLE 101
[0188] Pyrolysis of 1:15 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C.
and formation of carbon nanotubes--A sample (33.69 mg) of 1:15
hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 16
was heated at 30.degree. C./min to 250.degree. C. and held for 30
min. At this time, the sample was then heated at 10.degree. C./min
to 1000.degree. C. resulting in a weight retention of 82%. Raman
and x-ray studies confirmed the presence of carbon nanotubes in the
carbon nanotube-iron nanoparticle carbon composition. The
characteristic x-ray (111); (220), (222), and (422) reflections for
carbon nanotubes were readily apparent, whereas the bcc
iron-nanoparticle pattern was not evident. The lattice parameter
for carbon nanotubes was 5.972 .ANG.. The average size of carbon
nanotubes was 4.0 nm.
EXAMPLE 102
[0189] Formation of carbon nanotube fibers from 1:15
hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree.
C.--The 1:15 hexacarbonyldiiron complex of
1,2,4,5-tetrakis(phenylethynyl- )benzene (0.2 g) prepared as in
Example 16 was weighed into a test tube, wrapped with heating tape,
and melted by heating at 275-300.degree. C. resulting in an
increase in viscosity. Before gelation or solidification occurred,
a glass rod was pushed into the thick composition and removed
resulting in the formation of a fibrous glassy material. While
continuing to heat, the fibrous material solidified. At this time,
the fibrous material was removed, placed on a graphitic plate in a
tube furnace, and heated at 1.degree. C./min to 1000.degree. C. and
held for 1 hr. The fibrous sample was cooled at 0.5.degree. C./min
to room temperature. Raman and x-ray studies showed the presence of
carbon nanotubes and iron nanoparticles in the fiber. These results
indicate that carbon nanotube-iron nanoparticle containing fibers
can be formed from the precursor material containing iron by
thermally curing of a fiber, and further heat-treatment of the
fiber at elevated temperatures resulting in the formation of carbon
nanotube-iron nanoparticles-containing fibers with magnetic
properties.
EXAMPLE 103
[0190] Conversion of 1:10 nonacarbonyltriruthenium complex of
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotubes--A
sample (22.3 mg) of 1:10 nonacarbonyltriruthenium complex of
1,2,4,5-tetrakis(phenylethynyl)benzene prepared as in Example 17
was heated at 10.degree. C./min to 1400.degree. C. resulting in a
weight retention of 79%. Raman and x-ray studies confirmed the
presence of carbon nanotubes in the carbon nanotube-ruthenium
nanoparticle carbon composition. The characteristic x-ray (111),
(220), (222), and (422) reflections for carbon nanotubes were
readily apparent.
[0191] E. Formation of Carbon Nanotube Composition from a
Metal-Ethynyl Complex that is also a Metallocenyl Compound
EXAMPLE 104
[0192] Pyrolysis of 1:1 hexacarbonyldicobalt complex of
bis(ferrocenylethynyl)butadiyne and formation of carbon
nanotubes--A sample (40.77 mg) of hexacarbonyldicobalt complex of
bis(ferrocenylethynyl)butadiyne prepared as in Example 18 was
heated at 10.degree. C./min to 1000.degree. C. resulting in a
weight retention of 65%. A Raman spectrum showed the characteristic
sharp D and G lines and sharp second order absorption peaks between
2450 and 3250 cm.sup.-1. X-ray diffraction studies showed the
characteristic pattern attributed to formation of carbon
nanotubes.
EXAMPLE 105
[0193] Pyrolysis of 1:1 hexacarbonyldicobalt complex of
1-(ferrocenylethynyl)-4-(phenylethynyl)benzene and formation of
carbon nanotubes--A sample (16.45 mg) of 1:1 hexacarbonyldicobalt
complex of 1-(ferrocenylethynyl)-4-(phenylethynyl)benzene prepared
as in Example 19 was heated at 10.degree. C./min to 1000.degree. C.
resulting in a weight retention of 69%. A Raman spectrum showed the
characteristic sharp D and G lines and sharp second order
absorption peaks between 2450 and 3250 cm.sup.-1. X-ray diffraction
studies showed the reported characteristic peaks for the presence
of carbon nanotubes. The characteristic x-ray (111), (220), (222),
and (422) reflections for carbon nanotubes were readily apparent
along with the bcc cobalt nanoparticle pattern.
[0194] F. Formation of Carbon Nanotube Composition from
Metal-Ethynyl Complex and Ethynyl Compound
EXAMPLE 106
[0195] Pyrolysis of 50/50 molar mixture of 1:1 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene and pure
1,2,4,5-tetrakis(phenylethynyl)benzene and conversion to carbon
nanotubes-cobalt nanoparticle composition--1:1 Hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene (10.0 mg, 0.013
mmol) prepared as in Example 7 and pure C.sub.38H.sub.22 (6.3 mg,
0.013 mmol) were thoroughly mixed and heated at 10.degree. C./min
to 1000.degree. C. in a nitrogen atmosphere in a platinum TGA cup
using a TGA/DTA analyzer. The sample exhibited an endotherm at
197.degree. C. (m.p.), an exotherm at about 190.degree. C.
attributed to the reaction of the ethynyl groups to a thermoset,
and another exotherm at .apprxeq.843.degree. C. At 1000.degree. C.,
the sample showed a char yield of 77%. Raman and x-ray studies
confirmed the presence of carbon nanotubes in the carbon
nanotube-cobalt nanoparticle carbon composition. The x-ray
diffraction study showed the four characteristic reflection [(111),
(220), (222), and (422)] values for carbon nanotubes and the
pattern for fcc cobalt nanoparticles. The x-ray (111) reflection
for carbon nanotubes was readily apparent.
EXAMPLE 107
[0196] Thermal conversion of 50/50 molar mixture of 1:1
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-cobalt
nanoparticle composition--1:1 Hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (10.0 mg, 0.0131 mmol)
prepared as in Example 7 and 1,2,4,5-tetrakis(phenylethynyl)benzene
(6.3 mg, 0.0132 mmol) were thoroughly mixed and heated in a TGA
chamber at 10.degree. C./min to 1000.degree. C. Polymerization to a
shaped composition occurred during the initial heat-treatment up to
500.degree. C. During the heat-treatment, the sample showed an
endotherm at 197.degree. C. (m.p.) and an exotherm at 290.degree.
C. (polymerization reaction). After heating to 1000.degree. C., the
sample exhibited a char yield of about 70%. Raman study showed the
presence of carbon nanotubes. An x-ray diffraction study confirmed
the presence of carbon nanotubes-cobalt nanoparticle in the carbon
composition. The Raman spectrum showed sharp characteristic D and G
lines and not fully developed absorptions at 2400-3250 cm.sup.-1,
which indicates carbon nanotube formation in the early stage. The
x-ray diffraction study showed the four characteristic reflection
[(111), (220), (222), and (422)] values for carbon nanotubes and
the pattern for fcc cobalt nanoparticles. The x-ray (111)
reflection for carbon nanotubes was readily apparent. Raman and
x-ray studies confirmed the presence of carbon nanotubes-cobalt
nanoparticles in the carbon composition. The x-ray (111) reflection
value for carbon nanotubes was at 25.85.
EXAMPLE 108
[0197] Polymerization and conversion of 50/50 molar mixture of 1:1
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-cobalt
nanoparticle composition--1:1 Hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (10.0 mg, 0.0131 mmol)
prepared as in Example 7 and 1,2,4,5-tetrakis(phenylethynyl)benzene
(6.3 mg, 0.0132 mmol) were thoroughly mixed and heated in a TGA
chamber at 10.degree. C./min to 1000.degree. C. Polymerization to a
shaped composition occurred during the initial heat-treatment up to
500.degree. C. During the heat-treatment, the sample showed an
endotherm at 197.degree. C. (m.p.) and an exotherm at 290.degree.
C. (polymerization reaction). Raman and x-ray studies confirmed the
presence of carbon nanotubes in the carbon nanotube-cobalt
nanoparticle carbon composition. The x-ray diffraction study showed
the four characteristic reflection [(111), (220), (222), and (422)]
values for carbon nanotubes and the pattern for fcc cobalt
nanoparticles. The x-ray (111) reflection for carbon nanotubes was
readily apparent. Raman and x-ray studies confirmed the presence of
carbon nanotubes-cobalt nanoparticles in the carbon
composition.
EXAMPLE 109
[0198] Pyrolysis of 25/75 molar mixture of 1:1 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene and pure
1,2,4,5-tetrakis(phenylethynyl)benzene and conversion to carbon
nanotube-cobalt nanoparticle composition--1:1 Hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene (8.0 mg, 0.010
mmol) prepared as in Example 7 and pure C.sub.38H.sub.22 (15 mg,
0.0314 mmol) were thoroughly mixed and heated at 10.degree. C./min
to 1000.degree. C. in a nitrogen atmosphere in a platinum TGA cup
using a TGA/DTA analyzer. At 1000.degree. C., the sample showed a
char yield of 80%. The product was a powder and did not melt during
the heat-treatment. Raman and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-cobalt nanoparticle
carbon composition. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for fcc cobalt nanoparticles.
The x-ray (111) reflection for carbon nanotubes was readily
apparent.
EXAMPLE 110
[0199] Thermal conversion of 25175 molar mixture of 1:1
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-cobalt
nanoparticle composition--1:1 Hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (8.0 mg, 0.0105 mmol)
prepared as in Example 7 and 1,2,4,5-tetrakis(phenylethynyl)benzene
(15 mg, 0.0314 mmol) were thoroughly mixed and heated in a TGA
chamber at 10.degree. C./min to 1000.degree. C. resulting in a
shaped composition and a char yield of 71%. Raman and x-ray studies
confirmed the presence of carbon nanotubes-cobalt nanoparticles in
the carbon composition. The x-ray diffraction study showed the four
characteristic reflection [(111), (220), (222), and (422)] values
for carbon nanotubes and the pattern for fcc cobalt nanoparticles.
The x-ray (111) reflection for carbon nanotubes was readily
apparent. Raman and x-ray studies confirmed the presence of carbon
nanotubes-cobalt nanoparticles in the carbon composition.
EXAMPLE 111
[0200] Polymerization and conversion of 25/75 molar mixture of 1:1
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1,2,4,5-tetrakis(phenylethynyl)benzene to carbon nanotube-cobalt
nanoparticle composition--1:1 Hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (8.0 mg, 0.0105 mmol)
prepared in Example 7 and 1,2,4,5-tetrakis(phenylethynyl)benzene
(15 mg, 0.0314 mmol) were thoroughly mixed and heated in a TGA
chamber at 10.degree. C./min to 1000.degree. C. Raman and x-ray
studies confirmed the presence of carbon nanotubes in the carbon
nanotube-cobalt nanoparticle carbon composition. The x-ray
diffraction study showed the four characteristic reflection [(111),
(220), (222), and (422)] values for carbon nanotubes and the
pattern for fcc cobalt nanoparticles. The x-ray (111) reflection
for carbon nanotubes was readily apparent. Raman and x-ray studies
confirmed the presence of carbon nanotubes-cobalt nanoparticles in
the carbon composition.
EXAMPLE 112
[0201] Conversion of 50/50 weight mixture of 1:50
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C. to
carbon nanotubes--The 1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene (25 mg) prepared as in
Example 12 and 1,2,4,5-tetrakis(phenylethynyl)benzene (25 mg) were
thoroughly mixed and used for pyrolysis studies. A sample (26.34
mg) of the mixture was heated at 10.degree. C./min to 1000.degree.
C. under an inert atmosphere resulting in a weight retention of
84%. The Raman spectra showed the presence of carbon nanotubes.
X-ray diffraction study showed the formation of at least 75% carbon
nanotubes and about 25% carbon nanoparticles in the composition.
The x-ray (111), (220), (222), and (422) reflections for carbon
nanotubes were readily apparent. The lattice parameter for carbon
nanotube was 5.983A. The average size of carbon nanotubes was 4.14
nm.
EXAMPLE 113
[0202] Conversion of 50/50 weight mixture of 1:50
hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benzene and
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C.
for 1 hr to all carbon nanotubes--The 1:50 hexacarbonyldicobalt
complex of 1,2,4,5-tetrakis(phenylethynyl)benzene (25 mg) prepared
in Example 12 and 1,2,4,5-tetrakis(phenylethynyl)benzene (25 mg)
were thoroughly mixed and used for pyrolysis studies. A sample
(16.98 mg) of the mixture was heated at 10.degree. C./min to
1000.degree. C. and held for 1 hr under an inert atmosphere
resulting in a weight retention of 65%. The Raman spectra showed
the sharp peaks and the characteristic spectrum for carbon
nanotubes. X-ray diffraction study showed the characteristic
reported spectra for carbon nanotubes in the composition with a
strong peak (111) centered at about 25.85 (2-Theta value). The
x-ray (111), (220), (222), and (422) reflections for carbon
nanotubes were readily apparent, whereas little evidence of cobalt
nanoparticles was observed. The lattice parameter for carbon
nanotubes was 5.9739 .ANG.. The average size of carbon nanotubes
was 4.5 nm.
EXAMPLE 114
[0203] Formation of carbon nanotube fibers from 50/50 weight
mixture of 1:50 hexacarbonyldicobalt complex of
1,2,4,5-tetrakis(phenylethynyl)benze- ne and
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree.
C.--The mixture (0.2 g) prepared in Example 112 was weighed into a
test tube, wrapped with heating tape, and melted by heating at
275-300.degree. C. resulting in an increase in viscosity. Before
gelation or solidification occurred, a glass rod was pushed into
the thick composition and removed resulting in the formation of a
fibrous glassy material. While continuing to heat, the fibrous
material solidified. At this time, the fibrous material was
removed, placed on a graphitic plate in a tube furnace, and heated
at 1.degree. C./min to 1000.degree. C. and held for 1 hr. The
fibrous sample was cooled at 0.5.degree. C./min to room
temperature. Raman and x-ray studies showed the formation of carbon
nanotubes. These results indicate that carbon nanotube-containing
fibers can be formed from precursor material containing a trace
amount of cobalt by thermally curing to a shaped fiber, and further
heat-treated at elevated temperatures resulting in the formation of
carbon nanotube-containing fibers.
[0204] G. Formation of Carbon Nanotube Composition from Two
Metal-Ethynyl Complexes
EXAMPLE 115
[0205] Conversion of 50/50 mixture of 1:10 hexacarbonyldicobalt and
1:10 nonacarbonyltriruthenium complexes of
1,2,4,5-tetrakis(phenylethynyl)benz- ene heated to 1000.degree.
C.--The 50/50 molar mixture was prepared by taking the appropriate
1:10 cobalt (Example 9) and ruthenium (Example 17) complexes and
dissolving in 15 mL of methylene chloride. The desired mixture was
obtained by removal of solvent at reduced pressure. A sample (24.69
mg) of the mixture was heated at 10.degree. C./min to 1000.degree.
C. resulting in a weight retention of 76%. Raman (characteristic
pattern) and x-ray studies confirmed the presence of carbon
nanotubes in the carbon nanotube-metal nanoparticle carbon
composition. The characteristic x-ray (111), (220), (222), and
(422) reflections for carbon nanotubes were readily apparent.
EXAMPLE 116
[0206] Conversion of 50/50 mixture of 1:10 hexacarbonyldiiron and
1:10 nonacarbonyltriruthenium complexes of
1,2,4,5-tetrakis(phenylethynyl)benz- ene heated to 1000.degree.
C.--The 50/50 molar mixture was prepared by taking the appropriate
1:10 iron (Example 15) and ruthenium (Example 17) complexes and
dissolving in 15 mL of methylene chloride. The desired mixture was
obtained by removal of solvent at reduced pressure. A sample (23.51
mg) of the mixture was heated at 10.degree. C./min to 1000.degree.
C. resulting in a weight retention of 80%. Raman (characteristic
pattern) and x-ray studies confirmed the presence of carbon
nanoparticles-carbon nanotubes in the carbon nanotube-metal
nanoparticle carbon composition.
EXAMPLE 117
[0207] Conversion of 50/50 mixture of 1:10 hexacarbonyldiiron and
1:10 nonacarbonyltriruthenium complexes of
1,2,4,5-tetrakis(phenylethynyl)benz- ene heated to 1400.degree.
C.--The 50/50 molar mixture was prepared by taking the appropriate
1:10 iron (Example 15) and ruthenium (Example 17) complexes and
dissolving in 15 mL of methylene chloride. The desired mixture was
obtained by removal of solvent at reduced pressure. A sample (17.66
mg) of the mixture was heated at 10.degree. C./min to 1400.degree.
C. resulting in a weight retention of 80%. Raman (characteristic
pattern) and x-ray studies confirmed the presence of carbon
nanoparticles-carbon nanotubes in the carbon nanotube-metal
nanoparticle carbon composition. Raman (characteristic pattern) and
x-ray studies confirmed the presence of carbon nanotubes in the
carbon nanotube-metal nanoparticle carbon composition. The
characteristic x-ray (111), (220), (222), and (422) reflections for
carbon nanotubes were readily apparent.
[0208] H. Formation of Carbon Nanotube Composition from a Metal
Salt and an Ethynyl Compound
EXAMPLE 118
[0209] Synthesis of carbon nanotubes from 1/10 molar mixture of
hexacarbonyldicobalt and 1,2,4,5-tetrakis(phenylethynyl)benzene
heated to 1000.degree. C.--1,2,4,5-Tetrakis(phenylethynyl)benzene
(0.756 g, 0.157 mmol) and hexacarbonyldicobalt (0.0058 g, 0.0156
mmol) were weighed into an Al planchet and heated to 225.degree. C.
at reduced pressure for 20 minutes resulting in the rapid evolution
of volatiles at the beginning of the heating. Upon cooling, a
sample (21.79 mg) was heated at 10.degree. C./min to 1000.degree.
C. resulting in a weight retention of 77% weight. Raman
(characteristic pattern) and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-ruthenium nanoparticle
carbon composition. The characteristic x-ray (111), (220), (222),
and (422) reflections for carbon nanotubes were readily apparent.
The lattice parameter for carbon nanotubes was 5.9860 .ANG.. The
average size of carbon nanotubes was 4.8 nm. The average size of
the cobalt nanoparticles in the fcc phase was 10.0 nm.
EXAMPLE 119
[0210] Synthesis of carbon nanotubes from 1/20 molar mixture of
Fe.sub.2(CO).sub.9 and 1,2,4,5-tetrakis(phenylethynyl)benzene
heated to 1000.degree. C.--1,2,4,5-Tetrakis(phenylethynyl)benzene
(0.10 g, 0.21 mmol) and Fe.sub.2(CO).sub.9 (0.0038 g, 0.0104 mmol)
were weighed into an Al planchet and heated to 260.degree. C. at
reduced pressure for 5 minutes resulting in the rapid evolution of
volatiles at the beginning of the heating. Upon cooling, a sample
(28.82 mg) was heated at 10.degree. C./min to 1000.degree. C.
resulting in a weight retention of 80% weight. Raman
(characteristic pattern) and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-iron nanoparticle carbon
composition. The characteristic x-ray (111), (220), (222), and
(422) reflections for carbon nanotubes were readily apparent. The
x-ray pattern for iron nanoparticles (bcc phase) was very
small.
EXAMPLE 120
[0211] Synthesis of carbon nanotubes from 1/15 molar mixture of
Fe.sub.2(CO).sub.9 and 1,2,4,5-tetrakis(phenylethynyl)benzene mixed
in hexane before heating to 1000.degree.
C.--1,2,4,5-Tetrakis(phenylethynyl)- benzene (1.79 g, 3.74 mmol)
and Fe.sub.2(CO).sub.9 (0.091 g, 0.25 mmol) were weighed into an
100 mL flask. Hexane (50 mL) was added and the resulting mixture
was stirred rapidly for 5 minutes. The Fe.sub.2(CO).sub.9 dissolved
in the hexane without any color change. Upon concentrating at
reduced pressure, little particles of the Fe.sub.2(CO).sub.9 were
deposited homogeneously throughout the
1,2,4,5-tetrakis(phenylethynyl)benzene. A sample (35.50 mg) was
heated at 10.degree. C./min to 1000.degree. C. resulting in a
weight retention of 79% weight. Raman (characteristic pattern) and
x-ray studies confirmed the presence of carbon nanotubes in the
carbon nanotube-iron nanoparticle carbon composition. The
characteristic x-ray (111), (220), (222), and (422) reflections for
carbon nanotubes were readily apparent. The x-ray pattern for iron
nanoparticles (bcc phase) was very small.
EXAMPLE 121
[0212] Synthesis of carbon nanotubes from 1/20 molar mixture of
Ru.sub.3(CO).sub.12 and 1,2,4,5-tetrakis(phenylethynyl)benzene
heated to 1000.degree. C.--1,2,4,5-Tetrakis(phenylethynyl)benzene
(0.10 g, 0.21 mmol) and Ru.sub.3(CO).sub.12 (0.006 g, 0.0104 mmol)
were weighed into an Al planchet and heated to 260.degree. C. at
reduced pressure for 5 minutes resulting in the rapid evolution of
volatiles at the beginning of the heating. Upon cooling, a sample
(23.43 mg) was heated at 10.degree. C./min to 1000.degree. C. (1
hr) resulting in a weight retention of 77% weight. Raman
(characteristic pattern) and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-ruthenium nanoparticle
carbon composition. The characteristic x-ray (111), (220), (222),
and (422) reflections for carbon nanotubes were readily
apparent.
EXAMPLE 122
[0213] Synthesis and conversion of 1/10 molar mixing of
Ni(PPh.sub.3).sub.2(CO).sub.2 and
1,2,4,5-tetrakis(phenylethynyl)benzene mixed in methylene chloride
before heating to 1000.degree. C. and formation of carbon
nanotube-nickel nanoparticle composition--Ni(PPh.sub.-
3).sub.2(CO).sub.2 (0.17 g, 0.26 mmol) and
1,2,4,5-tetrakis(phenylethynyl)- benzene (1.26 g, 2.6 mmol) were
mixed in 40 mL of methylene chloride at room temperature. The
solvent was removed at reduced pressure. A sample (27.70 mg) of
mixture was heated at 10.degree. C./min to 1000.degree. C.
resulting in a weight retention of 76%. Raman (characteristic
pattern) and x-ray studies confirmed the presence of carbon
nanoparticles-carbon nanotubes-nickel carbide nanoparticles in the
resulting composition.
EXAMPLE 123
[0214] Synthesis and conversion of 1/10 molar mixing of Mn
(III)-2,4-pentanedionate and 1,2,4,5-tetrakis(phenylethynyl)benzene
mixed in methylene chloride before heating to 1000.degree. C. and
formation of carbon nanotube-manganese nanoparticle composition--Mn
(III)-2,4-pentanedionate (0.0296 g, 0.0.84 mmol) and
1,2,4,5-tetrakis(phenylethynyl)benzene (0.4020 g, 0.84 mmol) were
mixed in 40 mL of methylene chloride at room temperature. The
solvent was removed at reduced pressure. A sample (37.30 mg) of the
mixture was heated at 10.degree. C./min to 1000.degree. C.
resulting in a weight retention of 79%. Raman (characteristic
pattern) and x-ray studies confirmed the presence of carbon
nanoparticles-carbon nanotubes-manganese nanoparticle
composition.
EXAMPLE 124
[0215] Synthesis and conversion of 1/10 molar mixing of tungsten
hexacarbonyl and 1,2,4,5-tetrakis(phenylethynyl)benzene mixed in
methylene chloride before heating to 1000.degree. C. and formation
of carbon nanotube-tungsten nanoparticle composition--Tungsten
hexacarbonyl (0.0857 g, 0.24 mmol) and
1,2,4,5-tetrakis(phenylethynyl)benzene (1.16 g, 2.41 mmol) were
mixed in 40 mL of methylene chloride at room temperature. The
solvent was removed at reduced pressure. A sample (30.42 mg) of the
mixture was heated at 10.degree. C./min to 1000.degree. C.
resulting in a weight retention of 82%. Raman (characteristic
pattern) and x-ray studies confirmed the presence of carbon
nanoparticles-carbon nanotubes-tungsten nanoparticle
composition.
EXAMPLE 125
[0216] Synthesis and conversion of 1/10 molar mixing of
cyclopentadienyltungsten tricarbonyl dimer and
1,2,4,5-tetrakis(phenyleth- ynyl)benzene mixed in methylene
chloride before heating to 1000.degree. C. and formation of carbon
nanotube-tungsten nanoparticle
composition--Cyclopentadienyltungsten tricarbonyl dimer (0.0641 g,
0.096 mmol) and 1,2,4,5-tetrakis(phenylethynyl)benzene (0.4591 g,
0.96 mmol) were mixed in 25 mL of methylene chloride at room
temperature. The solvent was removed at reduced pressure. A sample
(30.21 mg) of the mixture was heated at 10.degree. C./min to
1000.degree. C. resulting in a weight retention of 82%. Raman
(characteristic pattern) and x-ray studies confirmed the presence
of carbon nanoparticles-carbon nanotubes-tungsten nanoparticle
composition.
EXAMPLE 126
[0217] Formation and conversion of 75/25 solvent mixing of 1/10
molar concentrations of cobalt and palladium solvent mixture of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C. to
carbon nanotube-cobalt/palladium alloy nanoparticle
composition--1/10 Cobalt and palladium molar mixtures of
1,2,4,5-tetrakis(phenylethynyl)ben- zene were prepared from
Co.sub.2(CO).sub.8 and Pd (II) acetylacetonate by solvent mixing. A
75/25 molar mixture was prepared from the 1/10 cobalt mixture
(0.0944 g, 0.124 mmol) and palladium mixture (0.0309 g, 0.0411
mmol) by dissolving in 20 mL of methylene chloride. The desired
mixture was obtained by removal of solvent at reduced pressure. A
sample (32.40 mg) of the 75/25 mixture was heated at 10.degree.
C./min to 1000.degree. C. resulting in a weight retention of 80%.
Raman (characteristic pattern) and x-ray studies confirmed the
presence of carbon nanotubes in the carbon nanotube-Co/Pd alloy
nanoparticle composition. The characteristic x-ray (111), (220),
(222), and (422) reflections for carbon nanotubes were readily
apparent along with fcc phase of cobalt-palladium nanoparticles.
This is the first time that the fcc phase of cobalt-palladium
nanoparticles has been observed. The composition is magnetic as
determined by its attraction to a bar magnet.
EXAMPLE 127
[0218] Formation and conversion of 50/50 solvent mixing of 1/10
molar concentrations of cobalt and palladium solvent mixture of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C. to
carbon nanotube-cobalt/palladium alloy nanoparticle
composition--1:10 Cobalt and palladium molar mixtures of
1,2,4,5-tetrakis(phenylethynyl)ben- zene were prepared from
Co.sub.2(CO).sub.8 and Pd (II) acetylacetonate by solvent mixing. A
50/50 molar mixture was prepared from the 1/10 cobalt mixture
(0.0673 g, 0.088 mmol) and palladium mixture (0.0661 g, 0.088 mmol)
by dissolving in 15 mL of methylene chloride. The desired mixture
was obtained by removal of solvent at reduced pressure. A sample
(23.20 mg) of the 50/50 mixture was heated at 10.degree. C./min to
1000.degree. C. resulting in a weight retention of 82%. Raman
(characteristic pattern) and x-ray studies confirmed the presence
of carbon nanotubes in the carbon nanotube-Co/Pd alloy nanoparticle
composition. The characteristic x-ray (111), (220), (222), and
(422) reflections for carbon nanotubes was readily apparent along
with fcc phase of cobalt-palladium nanoparticles. This is the first
time that the fcc phase of cobalt-palladium nanoparticles has been
observed. The composition is magnetic as determined by its
attraction to a bar magnet.
EXAMPLE 128
[0219] Formation and conversion of 25/75 solvent mixing of 1/10
molar concentrations of cobalt and palladium solvent mixture of
1,2,4,5-tetrakis(phenylethynyl)benzene heated to 1000.degree. C. to
carbon nanotube-cobalt/palladium alloy nanoparticle
composition--1/10 Cobalt and palladium molar mixtures of
1,2,4,5-tetrakis(phenylethynyl)ben- zene were prepared from
Co.sub.2(CO)8 and Pd (II) acetylacetonate by solvent mixing. A
25/75 molar mixture was prepared from the 1/10 cobalt mixture
(0.0229 g, 0.2997 mmol) and palladium mixture (0.0674 g, 0.0899
mmol) by dissolving in 20 mL of methylene chloride. The desired
mixture was obtained by removal of solvent at reduced pressure. A
sample (27.51 mg) of the 25/75 mixture was heated at 10.degree.
C./min to 1000.degree. C. resulting in a weight retention of 82%.
Raman (characteristic pattern) and x-ray studies confirmed the
presence of carbon nanotubes in the carbon nanotube-Co/Pd alloy
nanoparticle composition. The characteristic x-ray (111), (220),
(222), and (422) reflections for carbon nanotubes were readily
apparent along with fcc phase of cobalt-palladium nanoparticles.
This is the first time that the fcc phase of cobalt-palladium
nanoparticles has been observed. The composition is magnetic as
determined by its attraction to a bar magnet.
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