Patent Application
20150050459
The present invention relates to a 3D-shaped structure having a hydrophobic surface and a method of manufacturing the same.
Generally, a surface of a solid base material such as a metal or a polymer has intrinsic surface energy. This is exhibited by a contact angle between a liquid and a solid when a predetermined liquid comes into contact with the solid base material.
Water that is a representative liquid has a hydrophilic characteristic in that spherical water drops lose shapes thereof on the solid surface to wet the surface in the case where a size of the contact angle is less than 90°. Further, in the case where the size of the contact angle is more than 90°, water has a hydrophobic characteristic where water drops maintain spherical shapes on the solid surface and do not wet the surface but easily flow by a small external force.
If the intrinsic contact angle of the surface of the solid base material is changed, hydrophilicity and hydrophobicity may be further increased.
Particularly, if the hydrophobic surface is applied to a light distribution structure, sliding of a liquid flowing in a pipe becomes easier to increase a flux and a flow rate thereof. Accordingly, when the hydrophobic surface is applied to a water pipe or a boiler pipe, accumulation of impurities may be significantly reduced. Further, corrosion of an internal wall of the pipe may be prevented to reduce water pollution.
However, a technology of changing the contact angle of the solid surface for a predetermined purpose is a MEMS (microelectromechanical system) process where a semiconductor manufacturing technology is applied, and a high cost is required. Further, work such as oxidation of a metal surface, application of a predetermined temperature and voltage, and etching are performed, and thus a process is complicated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
Therefore, the present invention has been made in an effort to provide a 3D-shaped structure having a hydrophobic surface, and a method of manufacturing the same, in which a manufacturing process is simple and mass production is feasible at a low manufacturing cost.
An exemplary embodiment of the present invention provides a 3D-shaped structure having a hydrophobic surface, including: a substrate; a protrusion and depression portion formed on the substrate; and a protective film formed on a second protrusion and depression portion, in which the protrusion and depression portion includes at least one of a first protrusion and depression portion including a plurality of micro-protrusions and the second protrusion and depression portion including a plurality of nano-fibers.
The first protrusion and depression portion may include at least one selected from polypyrrole (PPy), polyaniline (PANI), and poly(3,4-ethylenedioxythiophene) (PEDOT).
The second protrusion and depression portion may include polyaniline.
The protective film may include Teflon or alkyltrichlorosilane.
The first protrusion and depression portion may have a thickness of 100 μm or less, and a height of the micro-protrusion may be 1 μm or less.
The second protrusion and depression portion may have a thickness of 1 μm or less, and the nano-fiber may have a diameter of 200 nm or less and a length of 1 μm or less.
Another exemplary embodiment of the present invention provides a method of manufacturing a 3D-shaped structure having a hydrophobic surface, including: forming a protrusion and depression portion on a substrate; and forming a hydrophobic protective film on the protrusion and depression portion, in which the forming of the protrusion and depression portion includes at least one of forming a first protrusion and depression portion including a plurality of micro-protrusions, and forming a second protrusion and depression portion including a plurality of nano-fibers.
The first protrusion and depression portion may be formed by electropolymerization, and the second protrusion and depression portion may be formed by chemical polymerization.
The electropolymerization may be performed in a water-soluble electrolyte solution including sodium dodecyl sulfate (SDS), hydrochloric acid (HCl), and pyrrole.
The chemical polymerization may be performed in an aqueous solution including 0.1 M to 1 M perchloric acid (HClO4), 1 mM to 10 mM ammonium persulfate (APS), and 1 mM to 50 mM aniline.
A method of manufacturing a 3D-shaped structure according to the exemplary embodiments of the present invention has merits in that hydrophobicity is provided to an internal surface or an external surface of the 3D-shaped structure, and the method is relatively low in price and simple.
The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.
The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
Hereinafter, a 3D-shaped structure having a hydrophobic surface according to an exemplary embodiment of the present invention will be specifically described with reference to the drawings.
As illustrated in
The substrate 100 can be any structure requiring the hydrophobic surface as a basic frame for obtaining the hydrophobic surface, and may be formed of a metal. For example, the substrate may be a structure requiring various functions, such as a pipe structure for separating oil and water, a gas exchange structure, and a sound wave penetrable anti-wetting structure.
The first protrusion and depression portion has a thickness of about 100 μm or less, and includes a plurality of micro-protrusions 200 having a height of about 1 μm or less.
The second protrusion and depression portion has a thickness of 1 μm or less, and includes a plurality of nano-fibers 300 having a diameter of 200 nm or less and a length of 1 μm or less.
The protective film 400 may be a material exhibiting a hydrophobic characteristic, for example, Teflon.
The 3D-shaped structure may be formed in the order illustrated in
As illustrated in
In the exemplary embodiment of the present invention, the structure having the hydrophobic surface may be simply manufactured at a low cost by performing the aforementioned steps. Moreover, in the exemplary embodiment of the present invention, the structure may be manufactured so that a hydrophobic characteristic is provided to an internal surface or an external surface of the 3D-shaped structure by the aforementioned manufacturing steps.
Hereinafter, the method of forming the 3D structure having the hydrophobic surface of
First, as illustrated in
The structure is a mesh having a mesh structure where a horizontal portion and a vertical portion cross each other, and a hole of the mesh may have a width of about 67 μm or less. The mesh may be formed of stainless steel.
As illustrated in
The first protrusion and depression portion may be formed by using electropolymerization, for example, may be formed by dipping the substrate in a water-soluble electrolyte solution including sodium dodecyl sulfate (hereinafter referred to as SDS), hydrochloric acid (HCl), and pyrrole, and then applying an electrical potential difference of 1 V to 1.5 V between the substrate and a platinum (Pt) electrode for 30 minutes to 60 minutes.
Thereafter, the first protrusion and depression portion is washed with deionized water, and then dried (S104). Drying is performed by using nitrogen gas or air having no reactivity with the first protrusion and depression portion.
As illustrated in
Chemical polymerization is performed by, for example, dipping in an aqueous solution including 0.1 M to 1 M perchloric acid (HClO4), 1 mM to 10 mM ammonium persulfate (hereinafter referred to as APS), and 1 mM to 50 mM aniline for 12 hours to 24 hours. In this case, a temperature of the aqueous solution is maintained at 0° C. to 15° C.
Then, the substrate on which the second protrusion and depression portion is formed is dipped in deionized water for 1 hour to be washed and then dried (S108). Drying is performed by using the nitrogen gas or air having no reactivity with the first protrusion and depression portion.
Then, as illustrated in
The protective film 400 may have a thickness of several tens of nanometers or less, and may be formed of Teflon or alkyltrichlorosilane.
The protective film 400 may be formed by diluting Teflon or alkyltrichlorosilane with 1H,1H,2H,2H-perfluoro-1-octanol (hereinafter referred to as FC-40), hexyltrichlorosilane (hereinafter referred to as HTS), dodecyltrichlorosilane (hereinafter referred to as DTS), or octadecyltrichlorosilane (hereinafter referred to as OTS) to apply diluted Teflon or alkyltrichlorosilane, or performing plasma polymerized fluorocarbon coating (hereinafter referred to as PPFC) and then performing curing at about 150° C. to 250° C. for about 10 minutes to about 60 minutes.
In the exemplary embodiment of the present invention, after the first protrusion and depression portion and the second protrusion and depression portion are formed, if the protective film 400 is formed on the second protrusion and depression portion, the substrate having an ultra-hydrophobic characteristic may be formed.
If the hydrophobic structure having the ultra-hydrophobic characteristic is formed, the structure having the hydrophobic characteristic is used for the purpose of, for example, provision of the hydrophobic characteristic to a pipe. Accordingly, the structure may be used in various functional devices such as a pipe structure for separating oil and water, a gas exchange structure, and a sound wave penetrable anti-wetting structure.
Hereinafter, the aforementioned exemplary embodiments of the present invention will be described in more detail through examples. However, the following examples are set forth for the purpose of the description, but are not to be construed to limit the scope of the present invention.
Forming of the 3D Structure having the Hydrophobic Surface
A stainless steel mesh having a hole diameter of 100 μm was prepared. The stainless steel mesh was washed with acetone, and washed with isopropyl alcohol and deionized water (DI water).
Then, the first protrusion and depression portion having the micro-protrusions made of polypyrrole (PPy) was formed on the stainless steel (SS) mesh through electropolymerization.
The electropolymerization was performed in a water-soluble electrolyte solution including 0.5 wt % of SDS, 0.01 M HCL, and 0.1 M pyrrole. In this case, an electrical potential difference of 1.5 V was applied to the stainless steel mesh and the Pt electrode for 30 minutes.
Referring to
Thereafter, the substrate on which the first protrusion and depression portion was formed was dipped in deionized water for 1 hour to remove SDS remaining on the first protrusion and depression portion, and dried by using the nitrogen gas.
Then, water molecules of the substrate on which the second protrusion and depression portion was formed were removed in an oven at 150° C., and the Teflon (Tef) layer was formed by dipping the substrate in the 0.5% Teflon solution diluted with FC-40. In addition, the Teflon layer was cured at 200° C. for 30 minutes to complete the protective film.
First, a stainless steel mesh having a hole diameter of 100 μm was prepared. The stainless steel mesh was washed with acetone, and washed with isopropyl alcohol and deionized water (DI water).
Then, the second protrusion and depression portion including the nano-fibers made of polyaniline (PANI) was formed on the stainless steel mesh by using chemical polymerization.
The chemical polymerization was performed by dipping the stainless steel mesh in an aqueous solution including 1 M HClO4, 6.7 mM APS, and 10 mM aniline for 12 hours. In this case, aniline monomers were mixed and reacted at a temperature of 0° C. to be polymerized.
Referring to
Thereafter, the substrate on which the second protrusion and depression portion was formed was dipped in deionized water for 1 hour to be washed and thus remove the mixture aqueous solution remaining on the second protrusion and depression portion, and dried by using the nitrogen gas.
Then, water molecules of the substrate on which the second protrusion and depression portion was formed were removed in an oven at 150° C., and the Teflon (Tef) layer was formed by dipping the substrate in a 0.5% Teflon solution diluted with FC-40. In addition, the Teflon layer was cured at 200° C. for 30 minutes to complete the protective film.
A stainless steel mesh having a hole diameter of 100 μm was prepared. The stainless steel mesh was washed with acetone, and washed with isopropyl alcohol and deionized water (DI water).
Then, the first protrusion and depression portion having micro-protrusions made of polypyrrole (PPy) was formed on the stainless steel (SS) mesh through electropolymerization.
The electropolymerization was performed in the water-soluble electrolyte solution including 0.5 wt % of SDS, 0.01 M HCL, and 0.1 M pyrrole. In this case, an electrical potential difference of 1.5 V was applied to the stainless steel mesh and the Pt electrode for 30 minutes. Thereafter, the substrate on which the first protrusion and depression portion was formed was dipped in deionized water for 1 hour to remove SDS remaining on the first protrusion and depression portion, and dried by using the nitrogen gas.
Then, the second protrusion and depression portion including the nano-fibers made of polyaniline (PANI) was formed on the first protrusion and depression portion by using chemical polymerization.
The chemical polymerization was performed by dipping the substrate having the first protrusion and depression portion in the aqueous solution including 1 M HClO4, 6.7 mM APS, and 10 mM aniline for 12 hours. In this case, aniline monomers were mixed and reacted at a temperature of 0° C. to be polymerized.
Referring to
Thereafter, the substrate on which the second protrusion and depression portion was formed was dipped in deionized water for 1 hour to be washed and thus remove the aqueous solution mixture remaining on the second protrusion and depression portion, and dried by using the nitrogen gas.
Then, water molecules of the substrate on which the second protrusion and depression portion was formed were removed in an oven at 150° C., and the Teflon (Tef) layer was formed by dipping the substrate in the 0.5% Teflon solution diluted with FC-40. In addition, the Teflon layer was cured at 200° C. for 30 minutes to complete the protective film.
Referring to
Confirmation of the Hydrophobic Characteristic of the 3D Structure having the Hydrophobic Surface
Example 1 is the Tef-PPy-Ss mesh, Example 2 is the Tef-PANI-SS mesh, and Example 3 is the Tef-PANI-PPy-SS mesh.
Comparative Example 1 is the stainless steel mesh (hereinafter referred to as SS mesh), and Comparative Example 2 is the mesh where the protective film formed of Teflon is formed on the stainless steel mesh (hereinafter referred to as Tef-SS mesh).
Referring to
In addition, it can be seen that as compared to Comparative Examples 1 and 2, in Examples 1 to 3, hysteresis is reduced. Hysteresis is an index exhibiting the degree of rolling of water drops, and the smaller the hysteresis is, the higher the hydrophobicity is. In Comparative Examples 1 and 2, the hysteresis value was 60° which was large, but in Examples 1 and 2, the hysteresis value was 10°, and in Example 3, the hysteresis value was less than 10°, and thus ultra-hydrophobicity was exhibited.
The static water contact angle (WCA) was measured between 5 μl ultra-pure water (DI water) drops and the surface of the nano-structure by a sessile drop method and an analysis system (DSA 100, Kruss, Germany).
Example 1 is the Tef-PPy-Ss mesh, Example 2 is the Tef-PANI-SS mesh, and Example 3 is the Tef-PANI-PPy-SS mesh.
Comparative Example 1 is the SS mesh, and Comparative Example 2 is the Tef-SS mesh.
Referring to
Referring to
However, it can be confirmed that Example 1 of the present invention has a value of 59.11%, Example 2 has a value of 76.06%, and Example 3 has a value of 92.15%, and thus the difference between the dynamic water pressure resistance value and the static water pressure resistance value is reduced to improve the hydrophobic characteristic.
Example 3 is the Tef-PANI-PPy-SS mesh, Comparative Example 1 is the SS mesh, and Comparative Example 2 is the Tef-SS mesh.
Herein, the water drops had the diameter of 2.5 mm, and collided at a speed of 1 m/s.
Referring to
However, referring to
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2012-0021203 | Feb 2012 | KR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR2012/006940 | 8/30/2012 | WO | 00 | 8/27/2014 |
