U.S. patent application number 14/766649 was filed with the patent office on 2015-12-24 for water and oil ultra-repellent structure and manufacturing method therefor.
This patent application is currently assigned to Kookmin University Industry Academy Cooperation Foundation. The applicant listed for this patent is KOOKMIN UNIVERSITY INDUSTRY ACADEMY COOPERATION FOUNDATION. Invention is credited to Sumit BARTHWAL, Si Hyung LIM.
Application Number | 20150368824 14/766649 |
Document ID | / |
Family ID | 51299921 |
Filed Date | 2015-12-24 |
United States Patent
Application |
20150368824 |
Kind Code |
A1 |
LIM; Si Hyung ; et
al. |
December 24, 2015 |
WATER AND OIL ULTRA-REPELLENT STRUCTURE AND MANUFACTURING METHOD
THEREFOR
Abstract
Provided are a superhydrophobic/superoleophobic structure and a
method of manufacturing the superhydrophobic/superoleophobic
structure. The superhydrophobic/superoleophobic structure includes:
a roughened primary structure formed on a surface of a metal base;
nanopores formed in the roughened primary structure; and a
hydrophobic/oleophobic layer formed on a surface of the roughened
primary structure. The superhydrophobic/superoleophobic structure
makes a large contact angle and a small sliding angle with both
aqueous solutions and oily solutions, thereby having a high degree
of superhydrophobicity/superoleophobicity. In addition, the
superhydrophobic/superoleophobic structure may be formed on large
or curved structural objects by the manufacturing method without
using a special device.
Inventors: |
LIM; Si Hyung; (Seoul,
KR) ; BARTHWAL; Sumit; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOOKMIN UNIVERSITY INDUSTRY ACADEMY COOPERATION FOUNDATION |
Seongbuk-gu Seoul |
|
KR |
|
|
Assignee: |
Kookmin University Industry Academy
Cooperation Foundation
Seoul
KR
|
Family ID: |
51299921 |
Appl. No.: |
14/766649 |
Filed: |
February 6, 2014 |
PCT Filed: |
February 6, 2014 |
PCT NO: |
PCT/KR2014/001036 |
371 Date: |
August 7, 2015 |
Current U.S.
Class: |
205/50 ;
205/190 |
Current CPC
Class: |
C25D 11/04 20130101;
C25D 11/08 20130101; C25D 11/16 20130101; C25D 11/18 20130101 |
International
Class: |
C25D 11/18 20060101
C25D011/18; C25D 11/16 20060101 C25D011/16; C25D 11/08 20060101
C25D011/08 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 8, 2013 |
KR |
10-2013-0014570 |
Claims
1. A superhydrophobic/superoleophobic structure comprising: a
roughened primary structure formed on a surface of a metal base;
nanopores formed in the roughened primary structure; and a
hydrophobic/oleophobic layer formed on a surface of the roughened
primary structure.
2. The superhydrophobic/superoleophobic structure of claim 1,
wherein the nanopores have a diameter of 1 nm to 300 nm.
3. The superhydrophobic/superoleophobic structure of claim 1,
wherein the nanopores have a diameter of 10 nm to 50 nm.
4. The superhydrophobic/superoleophobic structure of claim 1,
wherein the metal base is an aluminum (Al) base.
5. The superhydrophobic/superoleophobic structure of claim 1,
wherein the roughened primary structure comprises identical or
different sidewalls and plateaus that are continuously
arranged.
6. The superhydrophobic/superoleophobic structure of claim 5,
wherein each of the plateaus has a horizontal length within a range
of 500 .mu.m to 5 .mu.m.
7. The superhydrophobic/superoleophobic structure of claim 5,
wherein the nanopores are formed in the sidewalls and the plateaus
of the roughened primary structure in directions substantially
perpendicular to the sidewalls and the plateaus.
8. The superhydrophobic/superoleophobic structure of claim 1,
wherein the hydrophobic/oleophobic layer comprises fluorine
(F).
9. The superhydrophobic/superoleophobic structure of claim 8,
wherein the hydrophobic/oleophobic layer is a fluorine-containing
silane compound layer or a fluorine-containing thiol compound
layer.
10. The superhydrophobic/superoleophobic structure of claim 1,
wherein the hydrophobic/oleophobic layer is substantially not
formed inside the nanopores.
11. A method of manufacturing a superhydrophobic/superoleophobic
structure, the method comprising: etching a metal base with an acid
so as to form a roughened primary structure on the metal base;
anodizing the metal base on which the roughened primary structure
is formed, so as to form nanopores in the roughened primary
structure; and forming a hydrophobic/oleophobic layer on a surface
of the roughened primary structure.
12. The method of claim 11, wherein the anodizing of the metal base
is performed for 3 minutes to 25 minutes.
13. The method of claim 11, wherein the etching of the metal base
is performed by a wet etching method.
14. The method of claim 13, wherein the etching of the metal base
is performed using an acid solution.
15. The method of claim 11, wherein the metal base is an aluminum
(Al) base.
16. The method of claim 11, further comprising drying the metal
base at a temperature of 50.degree. C. to 200.degree. C. between
the etching of the metal base and the anodizing of the metal
base.
17. (canceled)
18. (canceled)
19. A superhydrophilic/superoleophilic structure comprising: a
roughened primary structure formed on a surface of a metal base;
and nanopores formed in the roughened primary structure.
20. The superhydrophilic/superoleophilic structure of claim 19,
wherein the nanopores have a diameter of 10 nm to 50 nm.
21. The superhydrophilic/superoleophilic structure of claim 19,
wherein the roughened primary structure comprises identical or
different sidewalls and plateaus that are continuously
arranged.
22. The superhydrophilic/superoleophilic structure of claim 21,
wherein each of the plateaus has a horizontal length within a range
of 500 nm to 5 .mu.m.
23. The superhydrophilic/superoleophilic structure of claim 19,
wherein a fluorine-containing compound is not formed on the
roughened primary structure.
24. A method of manufacturing a superhydrophilic/superoleophilic
structure, the method comprising: etching a metal base with an acid
so as to form a roughened primary structure on the metal base; and
anodizing the metal base on which the roughened primary structure
is formed, so as to form nanopores in the roughened primary
structure.
25. The method of claim 24, wherein the anodizing of the metal base
is performed for 3 minutes to 25 minutes.
26. The method of claim 24, wherein the etching of the metal base
is performed by a wet etching method.
27. The method of claim 26, wherein the etching of the metal base
is performed using an acid solution.
28. The method of claim 24, wherein the method does not comprise
forming a fluorine-containing compound layer on the roughened
primary structure.
29. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to a
superhydrophobic/superoleophobic structure and a method of
manufacturing the superhydrophobic/superoleophobic structure, and
more particularly, to a superhydrophobic/superoleophobic structure
having a very high degree of superhydrophobicity/superoleophobicity
and usable for imparting superhydrophobicity/superoleophobicity
even to curved or large structural objects without using a special
device, and a method of manufacturing the
superhydrophobic/superoleophobic structure.
BACKGROUND ART
[0002] Generally, hydrophobicity and oleophobicity refer to hardly
wettable properties with respect to water and oil. In the related
art, when the contact angle between a solid surface and water
contacting the solid surface is 150.degree. or greater and the
contact angle between the solid surface and oil contacting the
solid surface is 150.degree. or greater, the solid surface is
considered as having superhydrophobicity/superoleophobicity.
[0003] Much attention has been given to superhydrophobic surfaces
making a contact angle of 150.degree. or greater with water because
such surfaces are important in fundamental research and practical
applications. Superhydrophobicity and superoleophobicity refer to
hardly wettable properties of a material with respect to water and
oil. For example, contaminants are naturally removed from leaves of
plants, wings of insets, or wings of birds without any special
actions, or contaminants are not attached thereto. This is because
leaves of plants, wings of insets, and wings of birds have
superhydrophobicity.
[0004] Wettability is one of important properties of solid
materials and is mainly determined by both the chemical composition
and the geographical micro/nano structure of solid. There have been
increasing interest in wettable surfaces because of potential
applicability in various fields such as oil-water separation,
anti-reflection, anti-adhesion between bodily parts, anti-sticking,
anti-pollution, self washing, and turbulent flow prevention.
[0005] Aluminum has a high degree of thermal and electric
conductivity and is relatively light, inexpensive, and easily
machinable compared to copper. Therefore, aluminum is widely used
in many industrial fields. Recently, several methods of
manufacturing superhydrophobic aluminum have been reported.
However, much attention has not yet been given to methods of
imparting superhydrophobicity/superoleophobicity to aluminum
bases.
DETAILED DESCRIPTION OF THE INVENTION
Technical Problem
[0006] A first technical object of the present invention is to
provide a superhydrophobic/superoleophobic structure having a high
degree of superhydrophobicity/superoleophobicity and thus making a
large contact angle with aqueous solutions and oily solutions.
[0007] A second technical object of the present invention is to
provide a method of manufacturing a
superhydrophobic/superoleophobic structure for easily imparting
superhydrophobicity/superoleophobicity even to large or curved
structural objects without using a special device.
[0008] A third technical object of the present invention is to
provide an electronic device or a mechanical device including a
superhydrophobic/superoleophobic structure.
[0009] However, aspects of the present disclosure are not limited
thereto. Additional aspects will be set forth in part in the
description which follows, and will be apparent from the
description to those of ordinary skill in the related art.
Technical Solution
[0010] According to an inventive concept for realizing the first
technical object of the present invention, there is provided a
superhydrophobic/superoleophobic structure including: a roughened
primary structure formed on a surface of a metal base; nanopores
formed in the roughened primary structure; and a
hydrophobic/oleophobic layer formed on a surface of the roughened
primary structure.
[0011] The nanopores may have a diameter of 1 nm to 300 nm.
Preferably, the nanopores may have a diameter of 10 nm to 50 nm.
Particularly, the metal base may be an aluminum (Al) base.
[0012] In addition, the roughened primary structure may include
identical or different sidewalls and plateaus that are continuously
arranged. In this case, each of the plateaus may have a horizontal
length within a range of 500 nm to 5 .mu.m. In addition, the
nanopores may be formed in the sidewalls and the plateaus of the
roughened primary structure in directions substantially
perpendicular to the sidewalls and the plateaus.
[0013] In addition, the hydrophobic/oleophobic layer may include
fluorine (F). Particularly, the hydrophobic/oleophobic layer may be
a fluorine-containing silane compound layer or a
fluorine-containing thiol compound layer. In addition, the
hydrophobic/oleophobic layer may not be substantially formed in the
nanopores.
[0014] According to an inventive concept for realizing the second
technical object of the present invention, there is provided a
method of manufacturing a superhydrophobic/superoleophobic
structure, the method including: etching a metal base with an acid
so as to form a roughened primary structure on the metal base;
anodizing the metal base on which the roughened primary structure
is formed, so as to form nanopores in the roughened primary
structure; and forming a hydrophobic/oleophobic layer on a surface
of the roughened primary structure.
[0015] The anodizing of the metal base may be performed for 3
minutes to 25 minutes. In addition, the etching of the metal base
may be performed by a wet etching method. Particularly, the etching
of the metal base may be performed using a hydrochloric acid
solution. In addition, the metal base may be an aluminum (Al)
base.
[0016] Optionally, the method may further include drying the metal
base at a temperature of about 50.degree. C. to about 200.degree.
C. between the etching of the metal base and the anodizing of the
metal base.
[0017] According to an inventive concept for realizing the third
technical object of the present invention, there are provided an
electronic device or a device for transportation including the
superhydrophobic/superoleophobic structure. Non-limiting examples
of the electronic device and the device for transportation vehicles
may include: automobile/airplane/train/ship interior or exterior
devices; automobile/airplane/train/ship or home/office/industrial
heating, refrigerating, and air-conditioning systems (air
conditioners and heat pumps); televisions; cellular phones;
computer systems; portable computers; monitors; phones; printers;
keyboards; mouses; pumps; fluid transfer pipes; powder transfer
pipes; tanks storing fluids for transportation; illumination
devices; and backlight units.
Advantageous Effects of the Invention
[0018] The superhydrophobic/superoleophobic structure of the
present invention makes a very large contact angle with both
aqueous solutions and oily solutions owing to its superior
superhydrophobicity/superoleophobicity. In addition, the
superhydrophobic/superoleophobic structure may be formed on large
or curved structural objects by the manufacturing method of the
present invention without using a special device.
DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a perspective view illustrating a
superhydrophobic/superoleophobic structure according to an
embodiment of the inventive concept.
[0020] FIG. 2 is an enlarged view illustrating a portion II in FIG.
1.
[0021] FIG. 3 is a cross-sectional view illustrating one of
plateaus and one of sidewalls shown in FIG. 2.
[0022] FIG. 4 is a flowchart illustrating a method of manufacturing
a superhydrophobic/superoleophobic structure according to an
embodiment of the present invention.
[0023] FIG. 5 is a schematic cross-sectional view illustrating a
superhydrophilic/superoleophilic structure according to an
embodiment of the present invention.
[0024] FIGS. 6A and 6B are scanning electron microscope (SEM)
images of a surface of an aluminum base of Example 1 taken
immediately after operation 2 at magnifications of about 10,000
times and about 50,000 times, respectively.
[0025] FIGS. 7A and 7B are SEM images showing a surface of an
aluminum base at magnifications of about 10,000 times and about
50,000 times, respectively, the aluminum base being prepared by
setting the etching time in operation 2 of Example 1 to 6
minutes.
[0026] FIGS. 8A to 8D are SEM images of the surface of the aluminum
base of Example 1 taken immediately after operation 3 at
magnifications of about 10,000 times, about 30,000 times, about
100,000 times, and about 300,000 times, respectively.
[0027] FIGS. 9A and 9B are SEM images of a surface of an aluminum
base of Comparative Example 1 prepared through an anodizing
operation without operation 2 of Example 1, the SEM images being
taken immediately after the anodizing process at magnifications of
about 10,000 times and about 100,000 times.
[0028] FIG. 10 shows plan and side images of water, glycerol,
ethylene glycol (EG), olive oil, and hexadecane dripped on a
superhydrophobic/superoleophobic structure of Example 1.
[0029] FIG. 11 is a graph illustrating average contact angles of
water, glycerol, ethylene glycol, olive oil, and hexadecane with
each of samples prepared in Examples 2 to 5.
[0030] FIGS. 12A to 12F are sequential images taken when water and
olive oil were dripped onto a surface of a sample.
BEST MODE
[0031] The inventive concept will now be described in detail with
reference to the accompanying drawings, in which preferred
embodiments are illustrated. The inventive concept may, however, be
embodied in many different forms and should not be construed as
being limited to the embodiments set forth herein. The embodiments
are provided so that this disclosure will be thorough and complete,
and will fully convey the inventive concept to those skilled in the
art. In the accompanying drawings, like reference numerals refer to
like elements throughout. In addition, elements and regions are
schematically illustrated in the accompanying drawings. Therefore,
the inventive concept is not limited to relative sizes or distances
shown in the accompanying drawings.
[0032] Although terms such as first and second are used herein to
describe various elements, these elements should not be limited by
these terms. These terms are only used to distinguish one element
from other elements. For example, a first element may be termed a
second element, or a second element may be termed a first element
without departing from the teachings of the inventive concept.
[0033] In the following description, technical terms are used only
for explaining specific embodiments, and are not purposes of
limitation. The terms of a singular form may include plural forms
unless referred to the contrary. The meaning of `include` or
`comprise` specifies a property, a fixed number, a step, a process,
an element, a component, and a combination thereof but does not
exclude other properties, fixed numbers, steps, processes,
elements, components, and combinations thereof.
[0034] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by those of ordinary skill in the art to which the
inventive concept belong. It will be further understood that terms,
such as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0035] In the present disclosure, the slashes (/) used in
"hydrophobic/oleophobic" and "superhydrophobic/superoleophobic"
refer to "and." That is, the expression "hydrophobic/oleophobic"
indicates "hydrophobic and oleophobic," and the expression
"superhydrophobic/superoleophobic" indicates "superhydrophobic and
superoleophobic."
[0036] The present invention provides a
superhydrophobic/superoleophobic structure including: a roughened
primary structure formed on a surface of a metal base; nanopores
formed in the roughened primary structure; and a
hydrophobic/oleophobic layer formed on a surface of the roughened
primary structure.
[0037] FIG. 1 is a perspective view illustrating a
superhydrophobic/superoleophobic structure 100 according to an
embodiment of the inventive concept, and FIG. 2 is an enlarged view
illustrating a portion II in FIG. 1.
[0038] Referring to FIG. 1, the superhydrophobic/superoleophobic
structure 100 has a pipe shape. Although the
superhydrophobic/superoleophobic structure 100 is illustrated as
having a pipe shape in FIG. 1, the superhydrophobic/superoleophobic
structure 100 is not limited thereto. For example, the
superhydrophobic/superoleophobic structure 100 may have another
shape such as a planar shape, a curved shape, a spherical shape, or
a combination thereof.
[0039] The superhydrophobic/superoleophobic structure 100 may
include a metal such as copper (Cu), titanium (Ti), aluminum (Al),
tungsten (W), zinc (Zn), or tin (Sn) as a base material.
Particularly, the base material may preferably be aluminum (Al).
However, the base material is not limited thereto.
[0040] Referring to FIG. 2, the superhydrophobic/superoleophobic
structure 100 may include: plateaus 104 substantially parallel with
the surface of the superhydrophobic/superoleophobic structure 100;
and sidewalls 102 substantially perpendicular to the plateaus 104.
The expression "the sidewalls 102 are substantially perpendicular
to the plateaus 104" indicates that the sidewalls 102 connect the
plateaus 104 having various levels and help to distinguish the
plateaus 104 rather than the angle between the sidewalls 102 and
the plateaus 104 being definitely 90.degree..
[0041] In addition, the sidewalls 102 and the plateaus 104 may be
continuously arranged in a regular or irregular pattern along the
surface of the superhydrophobic/superoleophobic structure 100.
However, the sidewalls 102 and the plateaus 104 may not be entirely
formed along the surface of the superhydrophobic/superoleophobic
structure 100, but may be formed in a region of the surface of the
superhydrophobic/superoleophobic structure 100 which requires
superhydrophobicity/superoleophobicity.
[0042] In addition, the plateaus 104 may each have a horizontal
length W defined between the most distant two edge points and
ranging from about 500 .mu.m to about 5 .mu.m.
[0043] The sidewalls 102 and the plateaus 104 illustrated in FIG. 2
constitute a roughened primary structure 106. A plurality of
nanopores 110 may be formed in the roughened primary structure 106.
The nanopores 110 may have a pore diameter within the range of
about 1 nm to about 300 nm, more preferably about 10 nm to 50
nm.
[0044] If the nanopores 110 have an excessively large or small
diameter, the superhydrophobic/superoleophobic structure 100 may
not have superhydrophobicity/superoleophobicity. Without being
bound to a particular theory, if the diameter of the nanopores 110
is excessively large, the nanopores 110 may coalesce with each
other. In this case, a surface on which pillars are formed may
appear instead of a surface in which pores are formed, resulting in
poor superhydrophobicity/superoleophobicity. On the contrary, if
the diameter of the nanopores 110 is excessively small, the
nanopores 110 may contribute to
superhydrophobicity/superoleophobicity to a very low degree,
thereby also resulting in poor
superhydrophobicity/superoleophobicity.
[0045] The nanopores 110 may be defined as a secondary structure of
the superhydrophobic/superoleophobic structure 100. The nanopores
110 may extend in directions substantially perpendicular to the
plateaus 104 and the sidewalls 102. The expression "the nanopores
110 extend in directions substantially perpendicular to the
plateaus 104 and the sidewalls 102" indicates that the nanopores
110 extend in directions different from the surface directions of
the plateaus 104 and the sidewalls 102 rather than the nanopores
110 extending at an angle of 90.degree. to the plateaus 104 and the
sidewalls 102.
[0046] FIG. 3 is a cross-sectional view illustrating one of the
plateaus 104 and one of the sidewalls 102 shown in FIG. 2.
Referring to FIG. 3, it could be understood that a
hydrophobic/oleophobic layer 120 is formed on the plateaus 104 and
the sidewalls 102. The hydrophobic/oleophobic layer 120 may include
fluorine (F). In detail, the hydrophobic/oleophobic layer 120 may
include a fluorine-containing silane compound or a
fluorine-containing thiol compound.
[0047] The nanopores 110 are formed in each surface of the base
material 101, and entrances of the nanopores 110 are not covered
with the hydrophobic/oleophobic layer 120 but are opened. Methods
and materials that may be used to form the hydrophobic/oleophobic
layer 120 will be described in more detail when a method of
manufacturing the superhydrophobic/superoleophobic structure 100 is
described later.
[0048] Substantially, the hydrophobic/oleophobic layer 120 may not
be formed inside the nanopores 110.
[0049] FIG. 4 is a flowchart illustrating a method of manufacturing
a superhydrophobic/superoleophobic structure 100 according to an
embodiment of the present invention. Hereinafter, an explanation
will be given of the method of manufacturing a
superhydrophobic/superoleophobic structure 100 according to the
embodiment of the present invention.
[0050] Referring to FIG. 4, a metal base 101 is etched with an acid
so as to form a roughened primary structure 106 on the metal base
101 (S1). The metal base 101 may be etched in an acid solution for
about 10 seconds to about 10 minutes, preferably, about 1 minute to
5 minutes. In addition, the etching may be performed at room
temperature.
[0051] If the etching time is excessively short or long, the
roughened primary structure 106 including plateaus 104 and
sidewalls 102 may not be formed. The etching time is not limited to
the above-mentioned ranges. That is, the etching time may be
properly adjusted according to factors such as the kind of the
metal base 101, the kind of the acid, and the concentration of the
acid solution.
[0052] The acid may be an inorganic acid such as hydrochloric acid,
nitric acid, sulfuric acid, or phosphoric acid; an organic acid
such as organic acetic acid, organic sulfonic acid, or
perfluorinated carboxylic acid; or a mixture of one or more of the
limited acids. The acid may be used directly or after being diluted
with a solvent such as water. In the latter case, the acid may be
properly diluted according to properties of the acid. For example,
if the acid is hydrochloric acid, the acid may be diluted with
deionized water at a ratio of about 1:1 to about 1:5, preferably
about 1:2.
[0053] The metal base 101 may be simply immersed into the acid
solution to each the metal base 101 by a wet etching method. In
this case, a space such as a chamber may not be necessary, and even
if the metal base 101 is large, the metal base 101 may be easily
etched by the wet etching method.
[0054] Optionally, after the metal base 101 is etched, the metal
base 101 may be washed with deionized water (DI water) and may then
be dried at an increased temperature. The drying of the metal base
101 may be performed at about 50.degree. C. to about 200.degree. C.
for about 5 minutes to about 3 hours. However, the drying condition
of the metal base 101 is not limited thereto.
[0055] Thereafter, the metal base 101 is anodized (S2). Methods of
anodizing a metal material are well-known to those of ordinary
skill in the related art. For example, the metal base 101 may be
immersed into a sulfuric acid solution, an oxalic acid solution, an
citric acid solution, a sodium nitrate solution, a sodium chloride
solution, a chromic acid solution, or a phosphoric acid solution,
and a voltage may be applied to the metal base 101 serving as an
anode. The voltage may range from about 10 V to about 30 V. The
anodizing may be performed at room temperature for about 1 minute
to about 30 minutes, preferably 3 minutes to 25 minutes.
[0056] Like the wet etching method described above, since the
anodizing is simply performed by dipping the metal base 101 into a
solution, a room such as a chamber may not be necessary, and even
if the metal base 101 is large, the anodizing may be easily
performed.
[0057] Finally, a hydrophobic/oleophobic layer 120 is formed on the
metal base 101 (S3). The function of the hydrophobic/oleophobic
layer 120 is to modify the surface of the metal base 101. The
surface of the metal base 101 may be fluorinated to form the
hydrophobic/oleophobic layer 120. The metal base 101 may be dipped
into a hydrophobic/oleophobic treatment chemical so as to form the
hydrophobic/oleophobic layer 120.
[0058] A material such as a fluorine-containing silane compound, a
fluorine-containing thiol compound, or a fluorine-containing
polymer may be used to form the hydrophobic/oleophobic layer 120.
However, the hydrophobic/oleophobic layer 120 is not limited
thereto.
[0059] The metal base 101 may be coated with one or more of the
above-listed material to form the hydrophobic/oleophobic layer 120.
In this case, a coating method such as a spin-coating method or a
dip-coating method may be used. However, the coating method is not
limited thereto.
[0060] Non-limiting examples of one or materials that may be used
to form the hydrophobic/oleophobic layer 120 include a compound
having Formula 1 below:
(R.sub.1).sub.4-nSiX.sub.n [Formula 1]
[0061] In Formula 1, R1 is a fluoroalkyl group
"--(CH.sub.2).sub.p(CF.sub.2).sub.mCF.sub.3", X is selected from
the group consisting of hydrogen; a halogen selected from the group
consisting of F, Cl, Br, and I; a C.sub.1-C.sub.10 alkoxy group; a
C.sub.3-C.sub.8 aromatic alkoxy group; and a C.sub.2-C.sub.8
heteroaromatic alkoxy group having at least one heteroatom selected
from the group consisting of O, N, S, and P, n is an integer from 1
to 3, p is an integer from 0 to 3, and m is an integer from 0 to
17.
[0062] In more detail, non-limiting examples of one or materials
that may be used to form the hydrophobic/oleophobic layer 120
include: 1H,1H-perfluorooctyltrichlorosilane,
1H,1H-perfluorodecyltrichlorosilane,
1H,1H-perfluorododecyltrichlorosilane,
1H,1H-perfluorooctyltriethoxysilane,
1H,1H-perfluorodecyltriethoxysilane,
1H,1H-perfluorododecyltriethoxysilane,
1H,1H-perfluorooctyltrimethoxysilane,
1H,1H-perfluorodecyltrimethoxysilane,
1H,1H-perfluorododecyltrimethoxysilane,
1H,1H-perfluorooctyltridimethylchlorosilane,
1H,1H-perfluorodecyltridimethylchlorosilane,
1H,1H-perfluorododecyltridimethylchlorosilane,
1H,1H,2H,2H-perfluorooctyltrichlorosilane,
1H,1H,2H,2H-perfluorodecyltrichlorosilane,
1H,1H,2H,2H-perfluorododecyltrichlorosilane,
1H,1H,2H,2H-perfluorooctyltriethoxysilane,
1H,1H,2H,2H-perfluorodecyltriethoxysilane,
1H,1H,2H,2H-perfluorododecyltriethoxysilane,
1H,1H,2H,2H-perfluorooctyltrimethoxysilane,
1H,1H,2H,2H-perfluorodecyltrimethoxysilane,
1H,1H,2H,2H-perfluorododecyltrimethoxysilane,
1H,1H,2H,2H-perfluorooctyltridimethylchlorosilane,
1H,1H,2H,2H-perfluorodecyltridimethylchlorosilane,
1H,1H,2H,2H-perfluorododecyltridimethylchlorosilane,
3,3,3-trifluoropropyltrimethoxysilane,
3,3,3-trifluoropropyltriethoxysilane,
tridecafluorooctyltrimethoxysilanei,
tridecafluorooctyltriethoxysilane,
heptadecafluorodecyltrimethoxysilane,
heptadecafluorodecyltriethoxysilane,
pentafluorophenylpropyltrimethoxysilane,
pentafluorophenylpropyltriethoxysilane,
tetrakis(trifluoroacetoxy)silane, tris(trifluoroacetoxy)silane,
tetrafluorosilane, trifluorosilane, methyltrifluorosilane,
(tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane,
(tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane,
(heptadecafluoro-1,1,2,2-tetrahydrodecyl)triethoxysilane,
(heptadecafluoro-1,1,2,2-tetrahydrodecyl)trimethoxysilane,
heptadecafluorohexyltrimethoxysilane,
1-pentafluorosulfuranyl-3-triethoxysilylmethane,
1-pentafluorosulfuranyl-3-triethoxysilylethane,
1-pentafluorosulfuranyl-3-triethoxysilylpropane,
1-pentafluorosulfuranyl-4-triethoxysilylbutane,
1-pentafluorosulfuranyl-5-triethoxysilylpentane,
1-pentafluorosulfuranyl-6-triethoxysilylhexane,
1-pentafluorosulfuranyl-3-trimethoxysilyl-1-propene,
1-pentafluorosulfuranyl-4-trimethoxysilyl-1-butene,
1-pentafluorosulfuranyl-5-trimethoxysilyl-1-pentene,
1-pentafluorosulfuranyl-6-trimethoxysilyl-1-hexene,
(1,2,3,4,5-pentafluorosulfuranylphenyl)propyl trimethoxysilane,
perfluorodecanethiol, and pentafluorobenzenethiol.
[0063] In addition, non-limiting examples of one or materials that
may be used to form the hydrophobic/oleophobic layer 120 include a
polysiloxane-containing material. For example, the
polysiloxane-containing material may include one or more of linear,
branched, or cyclic polydimethylsiloxanes; polysiloxanes having a
hydroxyl group in the molecular chain such as silanol-terminated
polydimethylsiloxane, silanol-terminated polydiphenylsiloxane,
diphenylsilanol-terminated polydimethylsiloxane,
carbinol-terminated polydimethylsiloxane, hydroxypropyl-terminated
polydimethylsiloxane, and polydimethylhydroxyalkyleneoxide
methylsiloxane; polysiloxanes having an amino group in the
molecular chain such as bis(aminopropyldimethyl)siloxane,
aminopropyl-terminated polydimethylsiloxane, T-structured
polydimethylsiloxane having an aminoalkyl group,
dimethylamino-terminated polydimethylsiloxane, and
bis(aminopropyldimethyl)siloxane; polysiloxanes having a
glycidoxyalkyl group in the molecular chain such as
glycidoxypropyl-terminated polydimethylsiloxane, T-structured
polydimethylsiloxane having a glycidoxypropyl group,
polyglycidoxypropylmethylsiloxane, and a
polyglycidoxypropylmethyldimethylsiloxane copolymer; polysiloxanes
having a chlorine atom in the molecular chain such as
chloromethyl-terminated polydimethylsiloxane,
chloropropyl-terminated polydimethylsiloxane,
polydimethyl-chloropropylmethylsiloxane, chloro-terminated
polydimethylsiloxane, and
1,3-bis(chloromethyl)tetramethyldisiloxane; polysiloxanes having a
methacryloxyalkyl group in the molecular chain such as
methacryloxypropyl-terminated polydimethylsiloxane, T-structured
polydimethylsiloxane having a methacryloxypropyl group, and
polydimethyl-methacryloxypropylmethylsiloxane; polysiloxanes having
a mercaptoalkyl group in the molecular chain such as
mercaptopropyl-terminated polydimethylsiloxane,
polymercaptopropylmethylsiloxane, and T-structured
polydimethylsiloxane having a mercaptopropyl group; polysiloxanes
having an alkoxy group in the molecular chain such as
ethoxy-terminated polydimethylsiloxane, polydimethylsiloxane having
a trimethoxysilyl group on one terminal and a
polydimethyloctyloxymethylsiloxane copolymer; polysiloxanes having
a carboxyalkyl group in the molecular chain such as
carboxylpropyl-terminated polydimethylsiloxane, T-structured
polydimethylsiloxane having a carboxylpropyl group, and
carboxylpropyl-terminated T-structured polydimethylsiloxane;
polysiloxanes having a vinyl group in the molecular chain such as
vinyl-terminated polydimethylsiloxane,
tetramethyldivinyldisiloxane, methylphenylvinyl-terminated
polydimethylsiloxane, a vinyl-terminated
polydimethyl-polyphenylsiloxane copolymer, a vinyl-terminated
polydimethyl-polydiphenylsiloxane copolymer, a
polydimethyl-polymethylvinylsiloxane copolymer,
methyldivinyl-terminated polydimethylsiloxane, a vinyl terminated
polydimethylmethylvinylsiloxane copolymer, T-structured
polydimethylsiloxane having a vinyl group, vinyl-terminated
polymethylphenetylsiloxane, and cyclic vinylmethylsiloxane;
polysiloxanes having a phenyl group in the molecular chain such as
a polydimethyl-diphenylsiloxane copolymer, a
polydimethyl-phenylmethylsiloxane copolymer,
polymethylphenylsiloxane, a polymethylphenyl-diphenylsiloxane
copolymer, a polydimethylsiloxane-trimethylsiloxane copolymer, a
polydimethyl-tetrachlorophenylsiloxane copolymer, and
tetraphenyldimethylsiloxane; polysiloxanes having a cyanoalkyl
group in the molecular chain such as polybis(cyanopropyl)siloxane,
polycyanopropylmethylsiloxane, a polycyanopropyl-dimethylsiloxane
copolymer, and a polycyanopropylmethyl-methyphenylsiloxane
copolymer; polysiloxanes having a long-chain alkyl group in the
molecular chain such as polymethylethylsiloxane,
polymethyloctylsiloxane, polymethyloctadecylsiloxane, a
polymethyldecyl-diphenylsiloxane copolymer, and a
polymethylphenetylsiloxane-methylhexylsiloxane copolymer;
polysiloxanes having a fluoroalkyl group in the molecular chain
such as polymethyl-3,3,3-trifluoropropylsiloxane and
polymethyl-1,1,2,2-tetrahydrofluorooctylsiloxane; polysiloxanes
having a hydrogen atom in the molecular chain such as
hydrogen-terminated polydimethylsiloxane, polymethylhydrosiloxane,
and tetramethyldisiloxane; hexamethyldisiloxane; and a
polydimethylsiloxane-alkylene oxide copolymer. However, materials
that may be used to form the hydrophobic/oleophobic layer 120 are
not limited thereto.
[0064] After the hydrophobic/oleophobic layer 120 is formed on the
metal base 101 as described above, the metal base 101 may be heated
to a high temperature so as to fix the hydrophobic/oleophobic layer
120. For example, the metal base 101 may be heated within the
temperature range of about 40.degree. C. to about 150.degree. C.
for about 10 minutes to 3 hours. Optionally, the metal base 101 may
be washed with an organic solvent or deionized water before the
metal base 101 is heated.
[0065] If the heating temperature of the metal base 101 is
excessively high, the roughened primary structure 106 and the
nanopores 110 (secondary structure) may be damaged. On the other
hand, if the heating temperature of the metal base 101 is
excessively low, it may take a long time to fix the
hydrophobic/oleophobic layer 120.
[0066] The superhydrophobic/superoleophobic structure 100 described
above may be applied to various electronic devices or devices for
transportation. Examples of such electronic devices or devices for
transportation may include: automobile/airplane/train/ship interior
or exterior devices; automobile/airplane/train/ship or
home/office/industrial heating, refrigerating, and air-conditioning
systems (air conditioners and heat pumps); televisions; cellular
phones; computer systems; portable computers; monitors; phones;
printers; keyboards; mouses; pumps; fluid transfer pipes; powder
transfer pipes; tanks storing fluids for transportation;
illumination devices; and backlight units. The application of the
superhydrophobic/superoleophobic structure 100 is not limited
thereto. For example, components of heating, refrigerating, and air
conditioning systems for home/office/industrial applications such
as transportation vehicles including automobiles, airplanes, ships,
and trains may be treated to have hydrophobicity/oleophobicity for
preventing harmful substances or mold from growing on or adhering
to the components or removing such harmful substances or mold. In
this case, indoor areas may be protected from harmful substances or
mold, and thus pleasant environments may be provided. In addition,
surfaces on which the formation of ice or frost is retarded at
freezing temperatures may be realized using the above-mentioned
hydrophobic/oleophobic characteristics, and the surfaces may be
applied to components of heating, refrigerating, and
air-conditioning systems (air conditioners and heat pumps) for
home/office/industrial applications such as automobiles, airplanes,
and trains, so as to improve energy efficiency.
[0067] In addition, surprisingly it has been found that if the
hydrophobic/oleophobic layer 120 is not formed on the
superhydrophobic/superoleophobic structure 100, the
superhydrophobic/superoleophobic structure 100 has
superhydrophilicity/superoleophilicity. FIG. 5 is a schematic
cross-sectional view illustrating a
superhydrophilic/superoleophilic structure 200 according to an
embodiment of the present invention.
[0068] Referring to FIG. 5, the superhydrophilic/superoleophilic
structure 200 is formed by the same method as that used to form the
superhydrophobic/superoleophobic structure 100 except that a
hydrophobic/oleophobic layer forming process is not performed. The
superhydrophilic/superoleophilic structure 200 includes a roughened
primary structure 206 including plateaus 204 and sidewalls 202 and
formed on a base material 201. In addition, a plurality of pores
210 are formed in the plateaus 204 and the sidewalls 202. Since the
pores 210 are the same as the nanopores 110 of the
superhydrophobic/superoleophobic structure 100, a detailed
description thereof will not be repeated here.
[0069] The plateaus 204 may each have a horizontal length W defined
between the most distant two edge points and ranging from about 500
.mu.m to about 5 .mu.m.
[0070] In addition, according to an embodiment of the present
invention, the superhydrophilic/superoleophilic structure 200 may
be manufactured in the same manner as the method of manufacturing
the superhydrophobic/superoleophobic structure 100 described with
reference to FIG. 4 except that operation S3 for forming the
hydrophobic/oleophobic layer 120 is omitted. That is, the metal
base 201 may be etched with an acid so as to form the roughened
primary structure 206 on the metal base 201, and then the metal
base 201 may be anodized. The anodizing may be performed at room
temperature for about 1 minute to about 30 minutes, preferably 3
minutes to 25 minutes.
[0071] As described above, a hydrophobic/oleophobic layer is not
formed on the roughened primary structure 206. That is, a
fluorine-containing compound layer is not formed on the roughened
primary structure 206.
MODE OF THE INVENTION
[0072] Hereinafter, the configuration and effects of the present
invention will be described in detail with reference to specific
examples and comparative examples. However, the examples are for a
clearer understanding of the present invention and are not intended
to limit the scope of the present invention.
Example 1
[0073] Operation 1: a flat aluminum base (thickness: 0.81 mm, Al:
95.8 wt % to 98.6 wt %, Mg: 0.8 wt % to 1.2 wt %, Si: 0.4 wt % to
0.8 wt %, Cr: 0.04 wt % to 0.35 wt %, Cu: 0.15 wt % to 0.4 wt %,
Fe: 0.7 wt % max, Zn: 0.25 wt % max, Mn: 0.15 wt % max, and Ti:
0.15 wt % max) was washed using ultrasonic waves in acetone and
ethanol for 3 minutes and in deionized water (DI) for 3 minutes and
was then dried under a nitrogen atmosphere.
[0074] Operation 2: the washed aluminum base was etched for 3
minutes in a room-temperature acidic solution in which deionized
water and HCl are mixed at a volume ratio of 2:1. The etched
aluminum base was washed with deionized water and was then dried at
120.degree. C. for 1 hour.
[0075] FIGS. 6A and 6B are scanning electron microscope (SEM)
images showing a surface of the 3-minute etched aluminum base at
magnifications of 10,000 times and 50,000 times, respectively. As
shown in FIGS. 6A and 6B, a roughened primary structure having
sidewalls and plateaus was formed.
[0076] In addition, an aluminum base was etched for 6 minutes
independently of Example 1. FIGS. 7A and 7B are SEM images showing
a surface of the 6-minute etched aluminum base at magnifications of
10,000 times and 50,000 times, respectively. As shown in FIGS. 7A
and 7B, a roughened primary structure having various sidewalls and
plateaus was formed.
[0077] Operation 3: the dried aluminum base was anodized for 10
minutes in a 10.degree. C. sulfuric acid solution while applying a
constant voltage of 25 V. After the anodizing, the aluminum base
was rinsed with deionized water and dried in the air.
[0078] FIGS. 8A to 8D are SEM images taken from the surface of the
aluminum base at magnifications of 10,000 times, 30,000 times,
100,000 times, and 300,000 times immediately after the aluminum
base was anodized for 10 minutes. As shown in FIGS. 8A to 8D, many
fine pores were formed.
[0079] Operation 4: finally, the aluminum base treated as described
above was immersed for 8 minutes in a
1H,1H,2H,2H-perfluorooctyltrichlorosilane solution diluted with
n-hexane (solvent) to a concentration of 0.5%. Thereafter, the
aluminum base was taken away from the solution and was washed with
n-hexane. Then, the aluminum base was dried by heating the aluminum
base on a 100.degree. C. hot plate for 30 minutes. In this manner,
a superhydrophobic/superoleophobic structure (sample) was
prepared.
Comparative Example 1
[0080] A sample was prepared in the same manner as in Example 1
except that operation 2 was omitted.
[0081] FIGS. 9A and 9B are SEM images taken from a surface of an
aluminum base at magnifications of 10,000 times and 100,000 times
immediately after the aluminum base was anodized for 10 minutes. As
shown in FIGS. 9A and 9B, although many fine pores were formed, a
roughened primary structure was not formed.
Comparative Example 2
[0082] A sample was prepared in the same manner as in Example 1
except that operation 3 was omitted.
Comparative Example 3
[0083] A sample was prepared through operations 1 and 4 of Example
1 without performing operations 2 and 3 of Example 1.
[0084] The contact angles of water, glycerol, ethylene glycol,
olive oil, and hexadecane with each of the samples prepared in
Example 1 and Comparative Examples 1 to 3 were measured. Each of
the fluids was dripped to at least five points of each of the
samples in an amount of 5 .mu.l, and contact angles were measured
with SEO Phoenix 300 Touch. The contact angles were measured by a
tangent line method, and optical images of droplets were taken with
a SONY digital camera.
[0085] Averages of the measured contact angles are shown in Table
1.
TABLE-US-00001 TABLE 1 Fluid Surface tension Exam- Comparative
Comparative Comparative Kinds (mN/m) ple 1 Example 1 Example 2
Example 3 Water 72 163 153 157 110 Glycerol 63.6 159 150 152 102
Ethylene 48 158 147 147 86 glycol Olive Oil 32 153 134 145 74 Hexa-
27.5 150 126 139 54 decane Unit: degree (.degree.)
[0086] As shown in Table 1, although a hydrophobic/oleophobic layer
was formed on a smooth surface (Comparative Example 3), a large
contact angle could not be obtained. In contrast, when a roughened
primary structure and/or a secondary structure were formed (Example
1, and Comparative Examples 1 and 2), a relatively large contact
angle could be obtained.
[0087] Particularly, the superhydrophobic/superoleophobic structure
of Example 1 showed a significantly high degree of
hydrophobicity/oleophobicity compared to the other structures. The
structure of Example 1 showed a contact angle of 150.degree. or
greater with respect to olive oil and hexadecane but the structures
of Comparative Examples 1 to 3 did not showed high oleophobicity
with respect to olive oil and hexadecane.
[0088] FIG. 10 shows plan and side images of water, glycerol,
ethylene glycol (EG), olive oil, and hexadecane (in order of left
to right) dripped onto the superhydrophobic/superoleophobic
structure of Example 1. As shown in FIG. 10, the surface of the
superhydrophobic/superoleophobic structure showed a significantly
large contact angle, that is,
superhydrophobicity/superoleophobicity.
[0089] In addition, the sliding angles of water, glycerol, ethylene
glycol, olive oil, and hexadecane with respect to each of the
samples prepared in Example 1 and Comparative Examples 1 to 3 were
measured. Each of the fluids was dripped to at least five points of
each of the samples in an amount of 5 .mu.l, and sliding angles
were measured with SEO Phoenix 300 Touch. Averages of the measured
sliding angles are shown in Table 2.
TABLE-US-00002 TABLE 2 Fluid Surface tension Exam- Comparative
Comparative Comparative Kinds (mN/m) ple 1 Example 1 Example 2
Example 3 Water 72 2 6 21 N/A Glycerol 63.6 3 10 25 N/A Ethylene 48
4.3 16 N/A N/A glycol Olive Oil 32 5.3 35 N/A N/A Hexa- 27.5 20.6
N/A N/A N/A decane Unit: degree (.degree.)
[0090] As shown in Table 2, although a hydrophobic/oleophobic layer
was formed on a smooth surface (Comparative Example 3), a sliding
angle greater than a measurable angle limit was obtained. However,
when a roughened primary structure and/or a secondary structure
were formed (Example 1, and Comparative Examples 1 and 2), a
relatively small sliding angle was measured.
[0091] Particularly, the superhydrophobic/superoleophobic structure
of Example 1 showed a significantly high degree of
superhydrophobicity/superoleophobicity compared to the other
structures. The structure of Example 1 showed very small sliding
angles of about 5.degree. and about 20.degree. with respect to
olive oil and hexadecane, but the structures of Comparative
Examples 1 to 3 did not showed high oleophobicity with respect to
olive oil and hexadecane.
[0092] Therefore, even at a very small tilt angle, aqueous fluids
or oily fluids may easily slide off from the structure of Example
1.
[0093] In addition, samples were prepared in the same manner as in
Example 1 except that the anodizing time of the samples was varied
as described below, so as to evaluate the effect of the anodizing
time on hydrophobicity/oleophobicity.
Example 2
[0094] A sample was prepared in the same manner as in Example 1
except that anodizing was performed for 25 minutes.
Example 3
[0095] A sample was prepared in the same manner as in Example 1
except that anodizing was performed for 30 minutes.
Example 4
[0096] A sample was prepared in the same manner as in Example 1
except that anodizing was performed for 3 minutes.
Example 5
[0097] A sample was prepared in the same manner as in Example 1
except that anodizing was performed for 1 minute.
[0098] The contact angles of water, glycerol, ethylene glycol,
olive oil, and hexadecane with each of the samples prepared in
Examples 2 to 5 were measured, and averages of the measured contact
angles are calculated as shown in FIG. 11. The contact angles were
measured in the same manner as described above, and thus a detailed
description thereof is not repeated here.
[0099] Referring to FIG. 11, the contact angles were maximal when
anodizing was performed for 10 minutes and were slightly decreased
when anodizing was performed for 3 minutes or 25 minutes.
Particularly, when anodizing was performed for 1 minute or 30
minutes, the contact angles of olive oil and hexadecane were
significantly decreased.
Example 6
[0100] A sample was prepared in the same manner as in Example 1
except that operation 4 was omitted.
[0101] Although it was tried to measure the contact angles of
water, glycerol, ethylene glycol, olive oil, and hexadecane with a
surface of the sample, all of the fluids were absorbed in the
surface of the sample, and thus contact angles could not be
measured. That is, the contact angles of the fluids were
substantially zero.
[0102] FIGS. 12A to 12F are sequential images taken when water and
olive oil were dripped onto a surface of the sample. The left side
of each image shows water dripping from a pipette, and the right
side of each image shows olive oil dripping from a pipette.
[0103] Referring to FIG. 12A, droplets were suspended on ends of
the pipettes and were not yet delivered to the sample.
[0104] Referring to FIG. 12B, the droplet of olive oil was brought
into contact with the surface of the sample. Those of ordinary
skill in the art may understand that the contact angle of the
droplet of olive oil could not be yet measured because the droplet
of olive oil was not yet separated from the pipette.
[0105] Referring to FIG. 12C, the droplet of water was delivered
from the end of the left pipette to the sample. An unclear circle
on the end of the left pipette was an afterimage of the droplet of
water immediately before the droplet of water was delivered to the
sample. Actually, the droplet of water was completely delivered to
the sample and spread in a slightly convex shape.
[0106] Referring to FIG. 12D, the droplet of water considerably
spread, and a new droplet began to form on the end of the left
pipette. That is, although the droplet of water was delivered to
the surface of the sample, the droplet of water did not maintained
its shape on the surface of the sample, but the droplet of water
spread while being absorbed in the surface of the sample. That is,
the surface of the sample was superhydrophilic.
[0107] The droplet of olive oil was not yet completely separated
from the pipette. This was due to a slight difference between the
volumetric flow rates of the fluids and a difference between the
surface energy levels of the fluids caused by factors such as
different viscosity levels of the fluids. Therefore, it took
different times for the droplets of the fluids to leave the
pipettes.
[0108] Referring to FIG. 12E, the droplet of water spread over a
wider area, and the droplet of olive oil was completely separated
from the pipette. Although the droplet of olive oil looks having a
certain contact angle in the image of FIG. 12E, the droplet of
olive oil was actually in the middle of spreading. That is, the
contact angle of the olive oil could not be measured from the image
of FIG. 12E.
[0109] Referring to FIG. 12F, the droplet of olive oil spread over
a wider area compared to FIG. 12E, and thus the height of the
droplet of olive oil was significantly decreased. In FIG. 12F, the
droplet of olive oil did not form a contact angle with the surface
of the sample but spread while the edge of the droplet of olive oil
was being absorbed in the surface of the sample. That is, the
surface of the sample had superoleophilicity.
[0110] While preferred embodiments of the present invention have
been described in detail, it will be understood by those of
ordinary skill in the art that various changes in form and details
may be made therein without departing from the spirit and scope of
the present invention defined by the following claims. Therefore,
changes or modifications made in the embodiments of the present
invention should be construed as being within the scope of the
present invention.
REFERENCE NUMERALS
TABLE-US-00003 [0111] 100: Superhydrophobic/superoleophobic
structure 101: Metal base 102, 202: Sidewalls 104, 204: Plateaus
106, 206: Roughened primary structure 110, 210: nanopores 120:
Hydrophobic/oleophobic layer 200: Superhydrophilic/ superoleophilic
structure
INDUSTRIAL APPLICABILITY
[0112] The present invention may be usefully used in the electronic
industry and mechanical industry.
* * * * *