U.S. patent application number 15/040771 was filed with the patent office on 2016-06-09 for modified diamond particles.
The applicant listed for this patent is BRIGHAM YOUNG UNIVERSITY. Invention is credited to David Jensen, Matthew R. Linford, Landon A. Wiest.
Application Number | 20160158728 15/040771 |
Document ID | / |
Family ID | 42005481 |
Filed Date | 2016-06-09 |
United States Patent
Application |
20160158728 |
Kind Code |
A1 |
Linford; Matthew R. ; et
al. |
June 9, 2016 |
MODIFIED DIAMOND PARTICLES
Abstract
Modified diamond particles for use in chromatography with a
desired functional group at the diamond surface, formed from
reaction of hydroxyl groups at diamond surfaces with a reactive
molecule.
Inventors: |
Linford; Matthew R.; (Orem,
UT) ; Wiest; Landon A.; (Provo, UT) ; Jensen;
David; (Spanish Fork, UT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BRIGHAM YOUNG UNIVERSITY |
Provo |
UT |
US |
|
|
Family ID: |
42005481 |
Appl. No.: |
15/040771 |
Filed: |
February 10, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13526410 |
Jun 18, 2012 |
9283543 |
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15040771 |
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12557503 |
Sep 10, 2009 |
8202430 |
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13526410 |
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61191692 |
Sep 10, 2008 |
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Current U.S.
Class: |
436/178 ;
210/198.2; 560/162 |
Current CPC
Class: |
B01D 15/361 20130101;
B01D 15/3804 20130101; B01J 20/3253 20130101; Y10T 428/2991
20150115; B01J 20/287 20130101; B01J 20/3244 20130101; B01J 20/286
20130101; B01J 20/3246 20130101; B01D 15/206 20130101; B01J 20/3251
20130101; B01J 20/3204 20130101; B01J 20/3248 20130101; B01D 15/34
20130101; B01D 15/36 20130101; G01N 1/405 20130101 |
International
Class: |
B01J 20/32 20060101
B01J020/32; B01J 20/286 20060101 B01J020/286; B01D 15/20 20060101
B01D015/20; G01N 1/40 20060101 G01N001/40 |
Claims
1. A chemical separation apparatus, comprising: a stationary phase
including a plurality of diamond surfaces, each of at least some of
the plurality of diamond surfaces including a modified surface
having at least one of an acyl halide derivative or an isocyanate
derivative tethered to the modified surface through an ester
linkage or a urethane linkage respectively.
2. The chemical separation apparatus of claim 1 wherein the at
least one of the acyl halide derivative or the isocyanate
derivative provides steric hindrance from further reactions with at
least one of the diamond surface, the ester linkage, or the
urethane linkage.
3. The chemical separation apparatus of claim 1 wherein the acyl
halide or the isocyanate derivative is formed from an acyl halide
molecule or an isocyanate molecule having an electrophilic
site.
4. The chemical separation apparatus of claim 1 wherein the acyl
halide derivative or the isocyanate derivatives is formed from an
acyl halide or isocyanate molecule having a leaving group.
5. The chemical separation apparatus of claim 1 wherein the acyl
halide derivative or the isocyanate derivative is a reaction
product of one or more of alkyl isocyanate, aryl isocyanate, acid
chloride with aromatic group, acid chloride with alkyl group, or
acid bromide.
6. The chemical separation apparatus of claim 1 wherein the acyl
halide derivative or the isocyanate derivative includes one of or
more of alkyl groups or aryl groups.
7. The chemical separation apparatus of claim 6 wherein the acyl
halide derivative or the isocyanate derivative includes an alkyl
group with the formula --(CH.sub.2).sub.nCH.sub.3, where
n=0-25.
8. The chemical separation apparatus of claim 6 wherein the acyl
halide derivative or the isocyanate derivative includes an alkyl
group that is branched.
9. The chemical separation apparatus of claim 8 wherein the alkyl
group is branched after an .alpha.-carbon of the acyl halide or
isocyanate derivatives.
10. The chemical separation apparatus of claim 6 wherein the acyl
halide or isocyanate derivative is branched at an .alpha.-carbon
thereof.
11. The chemical separation apparatus of claim 6 wherein the acyl
halide derivative or the isocyanate derivative include an alkyl
group that is partially or fully fluorinated.
12. The chemical separation apparatus of claim 6 wherein the acyl
halide derivative or the isocyanate derivative includes an aryl
group that is partially or fully fluorinated.
13. The chemical separation apparatus of claim 1 wherein the
plurality of diamond particles are porous diamond particles.
14. The chemical separation apparatus of claim 1 wherein the at
least one of the acyl halide derivative or the isocyanate
derivative includes one or more functional groups near enough to
the ester linkage or the urethane linkage effective to provide
steric hindrance for further reactions at the diamond surface.
15. The chemical separation apparatus of claim 1 wherein the
chemical separation apparatus is configured as a solid phase
extraction column.
16. The chemical separation apparatus of claim 1 wherein the
chemical separation apparatus is configured as a chromatography
column.
17. The chemical separation apparatus of claim 16 wherein the
chromatography column is configured as a high-performance liquid
chromatography column, ultra-performance chromatography column, a
gel filtration column, an ion exchange column, or an affinity
separation column.
18. A chemical separation apparatus, comprising: a stationary phase
including a plurality of diamond surfaces, each of at least some of
the plurality of diamond surfaces including a modified surface
having at least one acyl halide derivative tethered to the modified
surface through an ester linkage.
19. A method of separating an analyte, the method comprising:
disposing a solution containing an analyte in a chemical separation
apparatus, the chemical separation apparatus including a stationary
phase including a plurality of diamond surfaces, each of at least
some of the plurality of diamond surfaces including a modified
surface having at least one of an acyl halide derivative or an
isocyanate derivative tethered to the modified surface through an
ester linkage or a urethane linkage respectively; and separating
the analyte from the solution with the chemical separation
apparatus.
20. The method of claim 19 wherein the at least one of the acyl
halide derivative or the isocyanate derivative provide steric
hindrance from further reactions with at least one of the diamond
surface, the ester linkage, or the urethane linkage.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/526,410, filed 18 Jun. 2012, which is a
divisional of U.S. patent application Ser. No. 12/557,503, filed 10
Sep. 2009, which claims priority from U.S. Provisional Patent
Application 61/191,692, filed 10 Sep. 2008, the disclosure of each
of the foregoing applications is hereby incorporated by this
reference.
BACKGROUND
[0002] Since the inception of modern chromatography, silica based
stationary phases have dominated the world of chemical separations.
Unfortunately, silica has certain limitations. Under acidic
conditions, silica tends to lose its functionality and under basic
conditions it dissolves entirely after a matter of hours. Not until
recently have alternatives to silica been available such as polymer
based stationary phases. These tend to swell when exposed to
organic solvents and are therefore not ideal for reversed-phase
separations.
[0003] Chemists have worked around the limitations of available
stationary phases, but these workarounds often result in less than
ideal outcomes. For instance, certain separations may need to occur
under basic or acidic conditions because the analyte of interest
may only be stable under a certain pH range. It is would therefore
be ideal to find a phase that could perform a separation under
extreme pHs that current phases cannot successfully do separations
at.
[0004] Diamond has usually been assumed to be inert and relatively
little has been done to investigate the possibility of diamond as
the basis for a stationary phase. Nosterenko et al. has performed
separations of proteins using oxidized/cleaned diamond and Saini et
al. has been successful in coating the diamond surface with
poly(allylamine). This coated diamond was then used as a normal
phase in Solid-phase Extraction (SPE). Saini's study also showed
that his phase was extremely stable under extreme pH conditions
(from pH 0-pH 14) for 24 h. The SPE column was able to be reused
many times and showed no signs of degradation. It also performed in
the same manner experiment after experiment and only required a
flush with ethyl acetate in between uses.
[0005] These two groups have shown that separations can indeed be
performed with diamond as the basis for a stationary phase.
Nesterenko's study lacked good resolution in it HPLC spectra and
Saini's capacity was quite low, but efforts are being made to
remedy the capacity issue.
CITED REFERENCES
[0006] [1] US Patent 20050189279
[0007] [2] US Patent 20040118762
SUMMARY
[0008] A new phase is directly bonded to the diamond surface which
has been largely hydroxyl terminated. In a specific example,
diamond cleaned with piranha solution is treated with lithium
aluminum hydride (LAH). This reaction greatly increases the amount
of hydroxyl groups on the diamond surface. Since hydroxyl groups
are reactive to various functional groups, this chemistry is
exploited to attach ligands directly to the diamond surface. For
example, isocyanates and acyl halides (primarily Br and CI) are
reactive to the hydroxyl functional group and form urethane and
ester linkages respectively, that are directly bonded to the
diamond surface. (See FIG. 1)
[0009] Bases do have the ability to hydrolyze this linkage at the
carbonyl site, so bulky groups (methyl, isopropyl, tert-butyl,
phenyl etc.) can be attached to the .alpha.-carbon of the ligand to
sterically hinder the binding site and prevent bases from accessing
the partially negative carbon. This should give this type of
linkage greater stability in the presence of acids and bases. The
reusability and consistency of the column is also expected to be
similar to that of Saini's column and this chemistry can be applied
to HPLC and SPE stationary phases.
[0010] An aspect is a method for preparing modified diamond
particles for use in chromatography where hydroxyl groups at the
diamond surfaces are reacted with a reactive molecule to introduce
a desired functional group at the diamond surface. An example is
the reaction of Isocyanates and acyl halides with
hydroxyl-terminated diamond to form HPLC/SPE stationary phases.
[0011] Another aspect is a method for preparing modified diamond
particles for use in chromatography where i) diamond particles are
reacted with an oxidizing agent that introduces carboxyl groups at
the surface of the diamond, ii) the carboxyl groups are reduced to
primary alcohols, and iii) the primary alcohols are reacted with a
reactive molecule to introduce a desired functional group at the
diamond surface.
[0012] The diamond particles of the present method can be used in
any suitable type of chromatography type. These include, for
example, high performance liquid chromatography (HPLC), ultra
performance liquid chromatography (UPLC), solid phase extraction,
electrochromatography, size-exclusion chromatography, ion
chromatography, affinity chromatography.
[0013] The chromatography may be practiced at any suitable
pressure, such as for example, between 1000 psi and 15000 psi.
[0014] The diamond surface may be prepared by reducing the surface
with a suitable reducing agent prior to reaction with the reactive
molecule. Any suitable reducing agent is contemplated, such as, for
example, lithium aluminum hydride.
[0015] The reactive function group may be any suitable functional
group with the desired reactivity, and may have attached to the
reactive group an alkyl group or aryl group. The alkyl group may
have the form --(CH.sub.2).sub.nCH.sub.3, where n=0-25. The alkyl
group may be branched or unbranched. The alkyl group may be
partially or fully fluorinated, The aryl group may have the form
--C.sub.6H.sub.6. The aryl group may be partially or fully
fluorinated.
[0016] Examples of the reactive functional groups include, one of
or a mixture of an alkyl isocyanate, an aryl isocyanate, an acid
chloride with an aromatic group, an acid chloride with an alkyl
group, an acid bromide, an alkyl halide, an aryl halide, a benzyl
halide, a benzyl triflate, a benzyl mesylate, an alkyl mesylate, an
alkyl tosylate, and an alkyl triflate.
[0017] The reactive functional group may contain more than one
other group near the reactive site of the molecule, which provides
steric hindrance for the adsorbed species.
[0018] The reactive molecule may contain C--H bonds. The reactive
molecule may contain an electrophilic site and a leaving group.
[0019] Another aspect is a diamond particle for use in
chromatography containing groups tethered to the diamond surface
through ether, ester, or urethane linkages.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1: Scheme outlining basic chemistry for the formation
of the isocyanate and acyl halide reacted diamond particles
[0021] FIG. 2: Spectra confirming the step by step synthesis of a
carbamide linked C.sub.18 chain to the diamond surface
[0022] FIG. 3: Possible examples of the types of groups attached at
the .alpha.-carbon site to increase sterics of the area in order to
prevent nucleophilic attack of a base at the carbonyl resulting in
hydrolysis of the ether or urethane linkage.
DETAILED DESCRIPTION
Example
Experimental
[0023] Micro-diamond or diamond powder is treated with piranha
solution (3:7 30% H.sub.2O.sub.2:conc. H.sub.2SO.sub.4) or any
other suitable cleaning/etching solution. This cleans/etches the
diamond surface and exposes the various functional groups that
naturally occur on the diamond surface. The diamond must be dried
thoroughly before the next step. This can be performed by pulling
argon through the powder or placing the powder in a vacuum for many
hours. The dryness can be verified by diffuse reflectance infrared
Fourier transform (DRIFT).
[0024] The cleaned dry diamond is then treated with 1M LiAlH.sub.4
(LAH) suspended in THF (or any other strongly reducing base) [1]
for 24-68 h at room temperature (about 1 g diamond:5 mL LAH
solution). Warning: LAH is extremely reactive to water. Use proper
PPE. The reaction must be performed under inert atmosphere (argon)
and all glassware must be dry. The reaction is quenched by 1M HCl.
This should be added very slowly due to the reactivity of LAH with
water and HCl. Once the reaction is quenched, the diamond is
filtered over a fine fritted Buchner funnel and washed with copious
amounts of water. If white particles are present, rinse with more 1
M HCl to dissolved the reacted LAH. Once thoroughly rinsed, the
powder is dried completely. This gives hydroxyl terminated
diamond.
[0025] The reduced surface has been disclosed US patent [1], the
reaction of the hydroxylated surface with various functional groups
is not disclosed. The present method is an improvement over the
disclosed diamond-based chromatographic processes.
[0026] Another US patent [2] discloses powders "attached with
hydrocarbon, amino, carboxylic acid, or sulfonic acid groups." The
present method is specifically targeting the reaction of the
hydroxylated surface with a reactive molecule to introduce a
desired functional group at the diamond surface, such as, for
example, reactive isocyanates and acyl halides, and this chemistry
and these functional groups are not disclosed.
[0027] In a specific example, for this final step the hydroxyl
terminated diamond is then placed in a reaction vessel which is
subsequently flushed with inert atmosphere. Then a reactive
molecule is added to the powder. For example, a desired isocyanate
or acyl halide is added to the powder (about 0.5 mL:1 g hydroxyl
terminated diamond) then add enough dry tetrahydrofuran (THF) or
ether to completely dissolve the isocyanate or acyl halide. The
reaction should then react for at least 18 h at room temperature.
Filter the diamond over a fine fritted Buchner funnel and wash with
a large amount of THF or ether to rinse away the unreacted
isocyanate or acyl halide. Dry the powder completely. The powder is
then suspended in a solvent and pressed into an HPLC column.
[0028] Results and Discussion
[0029] Thus far, only octadecyl isocyanate has been reacted with
the hydroxyl terminated diamond. The evidence of the successive
reactions can be seen in FIG. 2 by the DRIFT, ToF-SIMS and XPS
spectra. There is a decrease in the height of the alcohol peak
(3500 cm.sup.-1) seen in the octadecyl isocyanate DRIFT spectrum as
compared to the LAH spectrum. It is clear that not all of the
alcohol functional groups are reacted and this is attributed to the
steric hindrance of the diamond surface. The 2.degree. amine peak
at 3342.43 cm.sup.-1, asymmetric and symmetric C--H stretches at
2920.95 cm.sup.-1 and 2848.21 cm.sup.-1 and the carbonyl stretches
at 1612.33 cm.sup.-1 and 1572.64 cm.sup.-1 are indicative of
successful bonding of octadecyl isocyanate to the hydroxyl
terminated surface as evidenced by the urethane (carbamide)
linkage.
[0030] The ToF-SIMS data shows an increase of hydrocarbon fragments
in the positive ion spectra and a decrease of 0 (16 m/z) and OH (17
m/z) fragments in the negative ion spectra. This result is
predicted because fewer O and OH groups would be exposed on the
diamond surface once the isocyanate group has reacted with the OH
functional group. The XPS spectrum shows the presence of nitrogen
which is absent from the piranha and LAH treated diamond powders.
The only source of nitrogen in this experiment is from the
isocyanate group. This therefore further confirms the formation of
the carbamide linkage on the diamond surface.
[0031] In another embodiment, an HPLC column is packed with 5 .mu.m
octadecyl isocyanate reacted diamond powder. If non-porous diamond
is used, few plates are expected to be present on the column. This
should be remedied by using porous diamond powder.
[0032] The chemistry of the present method is expected to work with
various isocyanates and acyl halides, including compounds with the
disubstituted .alpha.-carbons (see FIG. 3 for some examples). The
acyl halide derivatives of these compounds would also be used
including the tert-butyl group not shown in the figure. Other
functional groups past the functionalized .alpha.-carbon could
include but are not limited to phenyl, naphthyl, chiral,
perfluorinated, C.sub.8, and C.sub.10.
CONCLUSION
[0033] The chemistry for creating urethane (carbamide) linkages to
the diamond surface is straight forward and should prove useful in
the creation of diamond-based HPLC and SPE stationary phases. The
attachment of octadecyl isocyanate to the diamond surface has been
verified and other isocyanates/acyl halides should also react in a
similar manner to the hydroxyl terminated diamond surface.
[0034] Once a diamond-based HPLC column is successfully created and
used, the added stability, reusability and consistency of these
diamond columns will exceed that of its similarly functionalize
silica-based counterparts. This strength comes from the urethane
and/or ester linkages which bind the diamond and the functional
group together. This will result in greater stability at more
extreme pHs and the disubstituted .alpha.-carbon should help
increase the stability further in basic conditions.
[0035] While invention has been described with reference to certain
specific embodiments and examples, it will be recognized by those
skilled in the art that many variations are possible without
departing from its scope and spirit, and that any invention, as
described by the claims, is intended to cover all changes and
modifications that do not depart from the spirit of the
invention.
* * * * *