U.S. patent application number 13/079367 was filed with the patent office on 2012-05-10 for urchin-like iron oxide and a method for producing the urchin-like iron oxide.
Invention is credited to Li-Chieh Hsu, Yuan-Yao LI, Hsin-Chih Yu.
Application Number | 20120114944 13/079367 |
Document ID | / |
Family ID | 46019900 |
Filed Date | 2012-05-10 |
United States Patent
Application |
20120114944 |
Kind Code |
A1 |
LI; Yuan-Yao ; et
al. |
May 10, 2012 |
URCHIN-LIKE IRON OXIDE AND A METHOD FOR PRODUCING THE URCHIN-LIKE
IRON OXIDE
Abstract
The present invention relates to an urchin-like iron oxide and a
method for producing the urchin-like iron oxide. The urchin-like
iron oxide comprises a core and multiple needle-like elongations
protruded from the core. The needle-like elongations could be wire,
rod, tube, cone, and flake. The length/width ratio of the
needle-like elongation is high enough to apply in an optoelectronic
field. The method in accordance with the present invention is to
stably heat an iron-contained powder under room temperature by a
thermal oxidation. The surface of the iron-contained powder is slow
oxidized to form an urchin-like iron oxide with multiple uniform
distributed needle-like elongations protruded from the surface. The
size of each needle-like elongation is easily adjusted and changed
by controlling the heating temperature. The method has advantages
of simplified operation and lowered expense.
Inventors: |
LI; Yuan-Yao; (Min-Hsiung,
TW) ; Yu; Hsin-Chih; (Zhubei City, TW) ; Hsu;
Li-Chieh; (Taichung City, TW) |
Family ID: |
46019900 |
Appl. No.: |
13/079367 |
Filed: |
April 4, 2011 |
Current U.S.
Class: |
428/402 ;
423/632 |
Current CPC
Class: |
C01G 49/06 20130101;
Y10T 428/2982 20150115; C01G 49/02 20130101; C01G 49/08 20130101;
C01G 49/04 20130101; B22F 1/02 20130101 |
Class at
Publication: |
428/402 ;
423/632 |
International
Class: |
C01G 49/02 20060101
C01G049/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 5, 2010 |
TW |
099138149 |
Claims
1. An urchin-like iron oxide, comprising: a core, being an iron
powder and have a surface; and multiple needle-like elongations,
being radically and radiated mounted on the surface of the iron
core and having a top portion protruded form the surface and a
connected portion mounted and conjugated on the surface of the
core.
2. The needle-like elongations as claimed in claim 1, wherein the
needle-like elongations are wire, rod, tube, cone, or flake.
3. The urchin-like iron oxide as claimed in claim 1, wherein each
needle-like elongation being at least 50 nanometers in length.
4. The urchin-like iron oxide as claimed in claim 3, wherein the
top portion of each needle-like elongation being at least 5
nanometers in diameter.
5. The urchin-like iron oxide as claimed in claim 4, wherein the
connected portion having a bottom is at least 30 nanometers in
width.
6. A method for producing an urchin-like iron oxide comprising
steps as following: providing a raw material: providing a grinded
iron-contained powder; and heating and oxidation: putting the
iron-contained powder on a plate and heating the iron-contained
powder by a stable temperature for a period.
7. The method for producing an urchin-like iron oxide as claimed in
claim 6, wherein the temperature being at least 220.degree. C.
8. The method for producing an urchin-like iron oxide as claimed in
claim 7, wherein the heating step form room temperature to the
stable temperature being increased by 1 to 20.degree. C. per
minute.
9. The method for producing an urchin-like iron oxide as claimed in
claim 8, wherein the iron-contained powder being heated for at
least half hour.
10. The method for producing an urchin-like iron oxide as claimed
in claim 9, wherein the heating and oxidation step having a
oxidation rate by an oxide is increased 0.2 to 1.5 wt %.
11. The method for producing an urchin-like iron oxide as claimed
in claim 10, wherein the heating and oxidation step being operated
under an atmosphere condition or an oxygen concentration by at
least 10 mole percentages.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an iron oxide and a method
for producing the iron oxide, especially relates to an urchin-like
iron oxide and a method for producing the urchin-like iron
oxide
BACKGROUND OF THE INVENTION
[0002] Iron oxide, such as iron(III) oxide, is a popular material
for producing an N-type semicomductor, has features of toxic-free
property, light stability, and great shield capability and is
widely applied in coating, catalytic, electrochemical and
bioengineering fields. However, the electrochemical properties of
iron oxide will be significantly affected by the particle size,
pore structure and form of an iron oxide particle.
[0003] The iron oxide particle might be spheral shaped with nano or
micro scale. Some researchers also try to produce screw or
urchin-like shaped iron oxide. Methods for producing specific iron
oxides include a hydrothermal synthesis and a template technique.
The hydrothermal synthesis uses a metallic oxide to form a
metal-surfactant precursor by reacting with a surfactant under a
water-free environment. Then the metal-surfactant precursor is
acted with a additive and some water so that the surfactant is
self-arranged spontaneously and the metallic oxide undergoes a
hydrolysis and poly-condensation process to form an urchin-like
iron oxide (Du and Cao, 2008). The template technique uses a micro
spheral-shaped sulfonate polystyrene as a hard template. The
sulfonate polystyrene reacts with an iron-contained solution in a
hydrothermal condition to form a urchin-shaped iron oxide. The
final step is to remove the template by a sintering process.
[0004] The urchin-like iron oxides in accordance with the above
mentioned methods just have urchin-shaped in geometry without
uniform needle-arrangement. Otherwise, the process of the
hydrothermal synthesis and the template formation of the template
technique are highly complexity so that the production cost will be
increased. The above two methods also have disadvantage of limiting
operation requirement such as specific atmosphere controlled or
solution formulated. Accordingly, it is difficult to precisely
control multiple parameters of the iron oxide and to form a
standardized urchin-like product.
SUMMARY OF THE INVENTION
[0005] The object of the present invention is to provide an
inventive urchin-like iron oxide. The urchin-like iron oxide
comprises an iron core has a surface and multiple needle-like
elongations that are mounted on protruded form the surface of the
iron core. The iron core is a fine powder and has nano scale in
diameter. The needle-like elongation has high length and width
ratio and could be broadly used in the electro-optical engineering
and the catalytic field.
[0006] Another object of the present invention is to provide a
method for producing an urchin-like iron oxide. The method has
advantages of simplified operation and lowered expense. The method
in accordance with the present invention is to stably heat an
iron-contained powder under room temperature by a thermal
oxidation. The surface of the iron-contained powder is slow
oxidized to form an urchin-like iron oxide with multiple uniform
distributed needle-like elongations protruded from the surface. The
size of each needle-like elongation is easily adjusted and changed
by controlling the heating temperature. The crystallized feature,
length, diameter and appearance of the needle-like elongations of
the urchin-like iron oxide are uniform. The ratio of the length and
width of the needle-like elongation is higher that is suitable for
applying in an optoelectronic field.
[0007] The above objects and advantages of the present invention
will become more readily apparent to those ordinarily skilled in
the art after reviewing the following detailed descriptions and
accompanying drawings in which:
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0008] FIG. 1 is structure of an urchin-like iron oxide in
accordance with the present invention.
[0009] FIG. 2 is a flow chart to show a method for producing an
urchin-like iron oxide in accordance with the present
invention.
[0010] FIG. 3A is a scanning electron microscopy graph of a first
embodiment shows appearance of an iron powder that is heated to
300.degree. C.
[0011] FIG. 3B is a scanning electron microscopy graph of the first
embodiment shows appearance of an iron powder that is heated to
300.degree. C. for half hour.
[0012] FIG. 3C is a scanning electron microscopy graph of the first
embodiment shows appearance of an iron powder that is heated to
300.degree. C. for an hour.
[0013] FIG. 3D is a scanning electron microscopy graph of the first
embodiment shows appearance of an iron powder that is heated to
300.degree. C. for 10 hours.
[0014] FIG. 4A is a scanning electron microscopy graph of a second
embodiment shows appearance of an iron powder that is heated to
350.degree. C.
[0015] FIG. 4B is a scanning electron microscopy graph of the
second embodiment shows appearance of an iron powder that is heated
to 350.degree. C. for an hour.
[0016] FIG. 4C is a scanning electron microscopy graph of the
second embodiment shows appearance of an iron powder that is heated
to 350.degree. C. for eight hours.
[0017] FIG. 5A is a scanning electron microscopy graph of a second
embodiment shows appearance of an iron powder that is heated to
400.degree. C.
[0018] FIG. 5B is a scanning electron microscopy graph of the
second embodiment shows appearance of an iron powder that is heated
to 400.degree. C. for half hour.
[0019] FIG. 5C is a scanning electron microscopy graph of the
second embodiment shows appearance of an iron powder that is heated
to 400.degree. C. for six hours.
[0020] FIG. 6 is an X-ray diffraction diagram of the urchin-like
iron oxide in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Please refer to FIG. 1, an urchin-like iron oxide (1) in
accordance with the present invention comprises an iron core (11)
and multiple needle-like elongations (12). The iron core (11) is
sphere and has a surface. The needle-like elongations (12) are
well, radically and radiated mounted on the surface of the iron
core (11). The needle-like elongations (12) could be wire, rod,
tube, cone, or flake. Each needle-like elongations (12) has a top
portion (111) and a connected portion (112) and has length at least
50 nanometer. The top portion (111) is protruded form the surface
and is at least 5 nanometers in diameter. The bottom portion (122)
is mounted and conjugated on the surface of the iron core and is at
least 10 nanometers in width.
[0022] With reference to FIG. 2, a method for producing an
urchin-like iron oxide in accordance with the present invention
comprises steps of:
[0023] providing a raw material (20): providing an iron-contained
fine powder as the raw material;
[0024] heating and oxidation (21) the raw material: putting the
iron-contained fine powder on a plate and heating the
iron-contained fine powder to a specific temperature for a
period.
[0025] In the heating and oxidation (21) step, the raw material is
heated from room temperature to at least 220.degree. C. for at
least half hour, preferably the heating rate is 1 to 20.degree. C.
per minute. In one embodiment, the heating and oxidation (21) step
is operated under atmosphere without applying a specific condition.
In another embodiment, the heating and oxidation (21) step is
operated under the oxygen concentration by at least 10 mole
percentages.
Example 1
[0026] The example 1 uses an iron powder as the raw material that
is heated to 300.degree. C. with the temperature is increased by
5.degree. C. per minute. With reference to FIGS. 3A to 3D, after
heated with 300.degree. C. for 30 minutes, the surface of the iron
powder is started to oxidation. After 2 hours, the surface of the
iron powder is disposed with a layer of oxide and starts to grow
multiple tiny protrudes with a top portion is 10 to 20 nanometers
in diameter. While heating to 10 hours, the protrudes of the
surface of the iron powder are extended to form an urchin-like iron
oxide particle with multiple needle-like elongations. In the
embodiment, the needle-like elongation has a top portion and a
connected portion. The length of the needle-like elongation is
between 1.8 to 2.2 micrometers. The diameter of the top portion of
each needle-like elongation is 20 to 30 nanometers. A ratio of the
diameter of the top portion and the length of the needle-like
elongation is about 86. Also, in this embodiment, the oxide is
increased by 0.26% per minute.
Example 2
[0027] The example 2 uses an iron powder as the raw material that
is heated to 350.degree. C. with the temperature is increased by
5.degree. C. per minute and then keeps heating by 350.degree. C.
for a period. With reference to FIGS. 4A to 4C, while staring to
heat the iron powder from room temperature for 30 minutes, the
surface of the iron powder starts to produce an oxide. After
heating for an hour, the surface of the iron powder is disposed by
layer of oxide with multiple tiny needle-like elongations that the
top portion is 20 to 30 nanometers in diameter. Once heating for 8
hours, the length and the diameter of the top portion of each
needle-like elongation is about 1.8 to 2.2 micrometers and 30 to 50
nanometers respectively. Therefore, a ratio of the diameter of the
top portion and the length of the needle-like elongation is about
53, and the oxide is increased by 0.26% per minute.
Example 3
[0028] The example 3 also uses an iron powder as the raw material
that is heated to 400.degree. C. with the temperature is increased
by 5.degree. C. per minute and then keeps heating by 400.degree. C.
for a period. With reference to FIGS. 5A to 5C, while staring to
heat the iron powder from room temperature for 30 minutes, the
surface of the iron powder starts to produce multiple needle-like
oxides and each oxide has a top portion with 40 to 60 nanometers in
diameter. After heating for six hours, the surface of the iron
powder is disposed by multiple tiny needle-like elongations and has
urchin-like appearance. In the sample 2, each needle-like
elongation is about 1.8 to 2.2 micrometers and 60 to 100 nanometers
respectively. Therefore, a ratio of the diameter of the top portion
and the length of the needle-like elongation is about 26, and the
oxide is increased by 1.24% per minute.
Example 4
[0029] With refer to FIG. 6, an X-ray diffraction diagram of the
urchin-like iron oxide in accordance with the present invention
indicates the urchin-like iron oxide comprises alpha-iron(II)
oxide, iron(III) oxide and alpha-iron. There are many needle-like
elongations disposed on the surface of the iron particle, therefore
the lattice planes with Miller indices (110) has higher intensity
than others. Otherwise, a peak (star symbol) shown at 45 degrees
indicates the iron particle does not oxidation completely.
[0030] With reference to FIGS. 3A.about.3D, 4A.about.4C and
5A.about.5C, while keeping to heat the iron particles with a stable
temperature, the surface of the iron particle is starting to react
with air and produces a lot of iron oxides (such as iron(II) oxide
or iron(III) oxide). With the heating period increased, the oxide
is delaminated by different kind of oxide. The outer layered oxide
is directly contacted and reacted with air. At a lower heating
temperature, the oxidation rate of the outer layered oxide is
slower than at a higher heating temperature so that the oxide are
tightly arranged on the surface of the iron powder.
[0031] Accordingly, the method for producing an urchin-like iron
oxide in accordance with the present invention has advantage of
easy operation and efficiently decreases the operation expense and
procedure. The ratio of the length and width of the needle-like
elongation of the urchin-like iron oxide is higher for applying in
an optoelectronic field.
* * * * *