KR100742696B1 - Method for fabricating surface of solid having micro/nano-scaled unevenness and solid surface treated by the same method - Google Patents

Abstract

The present invention relates to a method of forming a micro or nano-sized irregularities on the surface of a solid substrate to be processed into a hydrophilic surface, or a non-wetting coating to a hydrophobic surface, and a solid substrate having a hydrophilic / hydrophobic surface by such processing. .

In the method for processing a surface of a solid substrate according to the present invention, the spray nozzle of the particle injector is positioned to face the surface of the solid substrate, and the particle injector is driven to spray the fine particles onto the surface of the solid substrate to remove fine roughness. Forming a step.

The surface processing method may further include coating at least a portion of the surface of the solid substrate on which the fine irregularities are formed with a non-wetting material, or further comprising anodizing the surface of the solid substrate on which the fine irregularities are formed. Can be.

Fine iron, hydrophobic, hydrophilic, wetting, non-wetting, particle spray, anodic oxidation

Description

Surface treatment method of a solid substrate having fine irregularities, and a solid substrate surface-treated by the method TECHNICAL FIELD

1 is a perspective view illustrating a method for processing a surface of a solid substrate according to a first embodiment of the present invention.

2 is a perspective view showing a solid substrate having fine irregularities on the surface treated according to the surface processing method according to the first embodiment of the present invention.

3 is a perspective view illustrating a method of processing a surface of a solid substrate according to a second exemplary embodiment of the present invention.

4 is a cross-sectional view showing a solid substrate having fine irregularities on the surface treated according to the surface processing method according to the second embodiment of the present invention.

FIG. 5A is an electron micrograph of the surface of a solid substrate without surface treatment, FIG. 5B is an electron micrograph of the surface of a solid substrate having fine roughness treated by the surface processing method according to the first embodiment of the present invention, and FIG. An electron micrograph of the surface of a solid substrate having fine roughness treated by the surface treatment method according to the second embodiment of the present invention.

Figure 6a is a photograph measuring the fluid contact angle on the surface of the metal untreated, Figure 6b is a measurement of the fluid contact angle on the metal surface with fine roughness treated by the surface processing method according to the first embodiment of the present invention Figure 6c is a photograph of measuring the fluid contact angle on the non-wetting coating metal surface according to the surface processing method according to a second embodiment of the present invention.

Fig. 7 is a block diagram showing the apparatus for explaining the anodic oxidation process.

8A and 8B are a plan view and a cross-sectional view showing states before and after the anodic oxidation treatment step, respectively.

FIG. 9 is an electron micrograph of an aluminum surface on which nano-micron holes are formed after an aluminum anodic oxidation process.

10 is a cross-sectional view illustrating a surface of a solid substrate subjected to an anodizing process in accordance with a surface processing method according to a third embodiment of the present invention.

FIG. 11 is an electron micrograph of a surface of a solid substrate subjected to an anodization process in accordance with a surface treatment method according to a third embodiment of the present invention.

12 is a photograph showing a fluid contact state on a metal surface having fine roughnesses treated in accordance with a surface treatment method according to a third exemplary embodiment of the present invention.

* Explanation of symbols for main parts of drawings *

10: solid substrate 10a: surface of solid substrate

12: seasons 15: hydrophilic

16: non-wetting material 17: hydrophobic part

20: particle injector 21: injection nozzle

25 fine particles 31 non-wetting reagent

32: container 55: fluid

61: aluminum plate 62: alumina

63: electrolyte solution 65: negative electrode plate

13, 67: Micro Hall

The present invention relates to a surface treatment method of a solid substrate, and more particularly, to form a micro or nano-sized irregularities on the surface of the solid substrate to be processed into a hydrophilic surface, or to a hydrophobic surface by a non-wetting coating. And to a solid substrate having a hydrophilic / hydrophobic surface by such a process.

Generally, the surface of solid base materials, such as a metal and a polymer, has inherent surface energy. This results in a contact angle between the liquid and the solid when any liquid contacts the solid substrate. If the contact angle is smaller than 90 degrees, the spherical water droplets lose their shape on the solid surface and exhibit hydrophilicity that wets the surface. In addition, when the contact angle is larger than 90 degrees, the spherical water droplets show hydrophobicity easily flowing according to external force without wetting the surface while maintaining the spherical shape on the solid surface. If water droplets fall on the lotus leaf, the phenomenon of flowing through the surface without wetting the lotus leaf is the same.

On the other hand, the inherent contact angle of the surface of the solid substrate can be changed by processing the surface to have a fine concavo-convex shape. That is, a hydrophilic surface having a contact angle smaller than 90 degrees may have more hydrophilicity through surface treatment, and hydrophobic surfaces having a contact angle greater than 90 degrees may have greater hydrophobicity through surface treatment.

However, the technique for changing the contact angle of the solid surface for any application has been largely a method of forming micro or nano fine irregularities on the solid surface depending on the Microelectromechanical Systems (MEMS) process using semiconductor manufacturing technology. The MEMS process is a state-of-the-art technology that applies semiconductor technology mechanically, but the semiconductor process is a very expensive process.

In the case of forming nano irregularities on the metal surface, it is necessary to perform operations that are impossible in a general working environment such as oxidation of the metal surface, application of a constant temperature and voltage, and oxidation and etching in a special solution. In order to perform such a process, it is necessary to basically work in a specially designed clean room, which requires dedicated machines, and these machines are also expensive equipment.

Furthermore, due to the nature of the semiconductor process, the inability to treat a large surface at one time is also a disadvantage. As such, the existing technology has a very complicated process, is difficult to mass-produce, and is difficult to apply due to high production costs.

The present invention was devised to solve the above problems, and its object is to provide a surface processing method which can easily form a hydrophilic surface at low cost by forming fine roughness by spraying fine particles on the surface of a solid substrate. to provide.

Another object of the present invention is to provide a surface treatment method capable of forming a hydrophobic surface by performing a non-wetting coating treatment on a surface of a solid substrate having fine irregularities formed on the surface thereof.

It is still another object of the present invention to provide a surface treatment method capable of forming an extremely hydrophilic surface by subjecting the surface of a solid substrate having fine irregularities to the surface to be anodized again.

It is still another object of the present invention to provide a solid substrate having both hydrophobic and hydrophilic surfaces by forming fine irregularities on the surface and non-wetting coating of a portion thereof.

In order to achieve the above object, the method for processing the surface of a solid substrate according to the present invention comprises: positioning a spray nozzle of a particle injector to face the surface of the solid substrate, and driving the particle injector to fine particles of the solid substrate. Spraying the surface to form a fine roughness.

At this time, the particle injector may be used to select a sand blaster (sand blaster) for injecting sand particles, or a particle injector for injecting fine metal spheres, the solid substrate may be made of a metal or polymer material.

The surface processing method may further include coating at least a portion of the surface of the solid substrate on which the fine irregularities are formed with a non-wetting material. At this time, the non-wetting material may be applied to at least one material selected from the group consisting of PTFE (Polytetrahluoroethylene), FEP (Fluorinated ethylene propylene copolymer), PFA (Perfluoroalkoxy), SAM (Self assembled monolayer).

In addition, the surface processing method may further include anodizing the surface of the solid substrate on which the fine iron is formed. At this time, the solid substrate is preferably made of aluminum (Al) material.

According to the surface processing method of the present invention, it has a heterogeneous surface comprising a hydrophilic portion formed with fine irregularities on at least a portion of the surface, and a hydrophobic portion formed with a fine irregularity on at least another portion of the surface, and coated with a non-wetting material thereon. A solid substrate can be obtained.

In addition, according to the surface processing method of the present invention, it is possible to obtain a solid substrate having a micro-convex portion formed on at least a part of the surface, and a micro-hole formed in each of the micro-convex portions having a smaller size than this.

The fine concave-convex portion may be formed by spraying fine particles onto a surface with a particle injector, and the ultra-fine hole may be formed by anodizing.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are intended to illustrate the invention, but the invention is not limited thereto.

In order to clearly describe the present invention, a description of a configuration not related to the present invention is omitted, and the same reference numerals are attached to the same or similar elements throughout the specification.

1 is a perspective view illustrating a method for processing a surface of a solid substrate according to a first embodiment of the present invention.

Referring to FIG. 1, in order to perform the processing method according to the present embodiment, first, the injection nozzle 21 of the particle injector 20 is positioned to face the surface 10a of the solid substrate 10.

Next, the particle injector 20 is driven to spray the fine particles 25 onto the surface 10a of the solid substrate 10 to form fine roughness 12 having a size of several to several tens of micrometers. The fine particles 25 in the particle injector 20 are sprayed at a predetermined speed and pressure to impinge on the surface 10a of the solid substrate 10. In the collision process between the surface 10a of the solid substrate 10 and the fine particles 25, the surface 10a of the solid substrate 10 is subjected to impact energy, and thus the surface 10a of the solid substrate 10 is Cause deformation. The particle injector 20 may be, for example, a sand blast spraying sand particles, and may be processed by spraying fine particles such as metal balls instead of sand particles. Solid substrates that may be applied include metal plates such as aluminum, steel, copper, and the like.

 FIG. 2 is a perspective view showing a solid substrate having fine unevenness on the treated surface according to the first embodiment of the present invention, and a part thereof is enlarged and shown in cross section.

In the solid substrate 10 having the fine roughness 12 on the surface, the size of the fine roughness 12, that is, the height of the iron portion 12a or the depth of the concave portion 12b or the convex portion 12a Spacing between the) may vary depending on the particle injection speed, the injection pressure, and the size of the fine particles 25 of the particle injector 20, it can be adjusted by applying these values in advance.

Except for non-wetting materials, the contact angles of common solids, ie metals or polymers, are wetting materials of less than 90 degrees. When the surface of such a solid substrate is processed to have the fine concave-convex 12 according to the surface processing method according to the present embodiment, the contact angle becomes smaller, and the wettability becomes stronger.

3 is a perspective view illustrating a method for processing a surface of a solid substrate according to a second exemplary embodiment of the present invention, and FIG. 4 is a cross-sectional view showing a solid substrate having fine roughness on the treated surface.

In order to perform the surface processing method according to the present embodiment, first, the fine roughness 12 is formed on the surface of the solid substrate 10 according to the surface processing method according to the first embodiment.

Next, at least a part of the surface of the solid substrate 10 obtained through this is coated with the non-wetting material 16. As the non-wetting material 16, at least one material selected from the group consisting of PTFE (Polytetrahluoroethylene), FEP (Fluorinated ethylene propylene copolymer), PFA (Perfluoroalkoxy), and SAM (Self assembled monolayer) may be used.

As shown in FIG. 3, the solid substrate 10 having the fine irregularities 12 formed on the surface is coated by dipping in a container 32 containing a non-wetting reagent 31. 4, the solid substrate 10 having a surface divided into a hydrophilic portion 15, which is a surface showing hydrophilicity, and a hydrophobic portion 17, which is a surface showing hydrophobicity by being coated with a non-wetting material 16, as shown in FIG. 4. Can be produced.

The hydrophobic portion 17 has a wettability, and has a function to allow liquid such as water droplets to flow down into the sphere without getting wet on the surface. The hydrophilic portion 15 increases wettability to form a liquid film on the surface even with a small amount of liquid. It may have a function to form.

In this manner, the hydrophilic and hydrophobic surfaces are formed together on the same solid substrate 10 so that a portion (hydrophobic surface) is not condensed with water, and an application of inducing moisture to another portion (hydrophilic surface) is possible.

FIG. 5A is an electron micrograph of the surface of a solid substrate without surface treatment, FIG. 5B is an electron micrograph of the surface of a solid substrate having fine roughness treated by the surface processing method according to the first embodiment of the present invention, and FIG. An electron micrograph of the surface of a solid substrate having fine roughness treated by the surface treatment method according to the second embodiment of the present invention.

The solid substrate used in this experiment was aluminum, and the particle injector used was an industrial sandblaster, and was sprayed at a pressure of 6 kgf / cm 2 using gold steel particles of 500 mesh (diameter about 30 to 50 μm). In addition, the non-wetting material used was Teflon AF, and the coating method was spin coating for 30 seconds at 500 rpm.

5A to 5C, the surface 41 of the solid substrate treated by the surface treatment method according to the first embodiment is innumerable when compared to the surface 40 of the solid substrate which is not surface treated. It can be confirmed that it is formed on this surface.

The experiment which measured the contact angle in the surface of each solid base material surface-treated as mentioned above was performed.

The solid substrate and the processing method used in this experiment are the same as those applied in the experiments obtained in FIGS. 5A to 5C.

That is, the solid substrate used was aluminum, and the particle injector used was an industrial sandblaster, and was sprayed at a pressure of 6 kgf / cm 2 using gold steel particles of 500 mesh (diameter about 30 to 50 μm). The non-wetting material used was Teflon AF, and the coating method was spin coating for 30 seconds at 500 rpm. 5 μl of distilled water was used as the fluid used for the contact angle measurement.

Figure 6a is a photograph measuring the fluid contact angle on the surface of the metal untreated, Figure 6b is a measurement of the fluid contact angle on the metal surface with fine roughness treated by the surface processing method according to the first embodiment of the present invention Figure 6c is a photograph of measuring the fluid contact angle on the non-wetting coating metal surface according to the surface processing method according to a second embodiment of the present invention.

Referring to FIG. 6A, the contact angle of the fluid 55 was about 68 degrees on the surface 50 of the metal which was not processed. 6B, the contact angle of the fluid 55 is lowered by about 32 degrees in the surface 51 of the metal treated by the surface treatment method according to the first embodiment. That is, it showed the hydrophilicity that the wettability becomes large.

Referring to FIG. 6C, the contact angle of the fluid 55 is increased to about 153 degrees in the surface 52 of the metal on which the non-wetting coating is formed on the metal surface on which the fine roughness is formed according to the surface processing method according to the second embodiment. can confirm. In other words, a hydrophobic surface is implemented.

FIG. 7 is a block diagram illustrating an apparatus for explaining the anodic oxidation process, and FIGS. 8A and 8B are a plan view and a diagram showing states before and after the anodic oxidation process, respectively.

As shown in FIG. 7, when the aluminum plate 61 is immersed in the electrolyte solution 63, the anode is placed on the aluminum plate 61, and the cathode is placed on the other cathode plate 65. And (b), an alumina 62, which is an oxide film, is formed on the surface of the aluminum plate 61, and an ultra-fine hole 67 in nanometer units is formed. Phosphoric acid (H ₃ PO ₄ ) or oxalic acid (C ₂ H ₂ O ₄ ) may be used as the electrolyte 63.

9 is an electron micrograph of an aluminum surface on which nano-fine holes 67 are formed in nanometers after anodizing.

10 is a cross-sectional view illustrating a surface of a solid substrate subjected to an anodizing process in accordance with a surface processing method according to a third embodiment of the present invention.

In order to perform the surface processing method of the solid substrate according to the third embodiment of the present invention, first, the fine iron 12 is formed on the surface of the solid substrate 10 according to the surface processing method according to the first embodiment.

Next, the surface of the solid substrate 10 obtained through this is anodized as described above. As a result, as shown in FIG. 10, the micro-shaped concave-convex 12 in which the micro-holes 13 of nano units, that is, several to several tens of nanometers in size, are additionally formed on the surface of the micro-convex concave 12 formed by using the particle injector. ) Can be formed.

FIG. 11 is an electron micrograph of a solid substrate subjected to anodization in accordance with a surface treatment method according to a third embodiment of the present invention.

It can be seen that the ultra-fine hole 13 is formed on the surface of each fine groove 12 formed by the surface processing method according to the first embodiment.

FIG. 12 is a photograph showing a fluid contact state on a metal surface 71 having fine roughness processed according to the surface processing method according to the third embodiment of the present invention.

The solid substrate used here was aluminum, and 500 mesh (diameter about 30-50 micrometers) of fine steel yarn particles were sprayed using the sand blaster at the pressure of 6 kgf / cm <2>.

0.3M aqueous solution of oxalic acid (C ₂ H ₂ O ₄ ) was used as the electrolyte solution used in the anodizing process, which is an additional processing step in this embodiment, wherein the temperature of the aqueous solution was 15 degrees Celsius and the applied voltage was 40V. _DC .

As shown in FIG. 12, the contact angle of the fluid 55 is extremely low to an unmeasurable degree, so that the hydrophilic surface can be processed.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

As described above, according to the surface processing method of the solid substrate according to the present invention, a hydrophilic surface can be easily formed by forming fine iron on the surface of the solid substrate through a simple and inexpensive manufacturing process, and a non-wetting coating on such surface. Treatment can form a hydrophobic surface. In addition, by forming a fine roughness on the surface by using a particle injector, an anodizing treatment can be formed to form an extremely hydrophilic surface.

Solid substrates having the hydrophilic / hydrophobic surface thus formed can be applied to a variety of applications.

That is, the moisture can be controlled by the condensation induction action, can be applied to the condenser of the air conditioning system to increase the condensation efficiency, it is possible to shorten the recycling process by leaving no residue in the beverage can. In addition, it is possible to prevent the phenomenon of steaming due to the temperature difference between the outside of the glass inside the vehicle in winter, and to increase the driving force by applying to the surface of the ship where the resistance to water is very important. In addition, it can be applied to the surface of dish-type antenna, which is a problem due to winter snow accumulation, and can be applied to the entire industry, such as increasing the flow rate by applying it to a water supply pipe.

On the other hand, it is also possible to form a hydrophilic and hydrophobic surface together in the same solid substrate so that a portion (hydrophobic surface) does not form moisture and induces water to another portion (hydrophilic surface).

Claims (17)

delete delete delete Positioning the spray nozzle of the particle injector opposite the surface of the solid substrate; Driving the particle injector to spray fine particles onto the surface of the solid substrate to form fine roughness to have hydrophilicity; And Anodizing the surface of the solid substrate on which the fine irregularities are formed to improve hydrophilicity to form an ultrafine hole having a deeper depth than the diameter. Surface processing method of a solid substrate comprising a. The method of claim 4, wherein The solid substrate is a surface processing method of a solid substrate, characterized in that made of aluminum (Al) material. The method according to claim 4 or 5, The particle injector is a sand blaster (sand blaster) for injecting sand particles, characterized in that the surface treatment method of a solid substrate. The method according to claim 4 or 5, And the particle injector is a particle injector for injecting fine metal spheres. delete A hydrophilic portion in which fine irregularities are formed on a part of the surface; And Hydrophobic zones with fine grains formed on other parts of the surface and coated with a non-wetting material thereon Solid substrate having a heterogeneous surface comprising together. The method of claim 9, Wherein said hydrophilic portion is formed by spraying fine particles onto a surface with a particle injector. The method of claim 9, The non-wetting material is a solid substrate having a heterogeneous surface, characterized in that at least one material selected from the group consisting of PTFE (Polytetrahluoroethylene), FEP (Fluorinated ethylene propylene copolymer), PFA (Perfluoroalkoxy), SAM (Self assembled monolayer) . Fine irregularities formed on a part of the surface; And It is formed in a smaller size than the fine concave portion to improve the hydrophilicity, the ultra-fine hole deeper than the diameter Solid substrate having a hydrophilic surface comprising a. The method of claim 12, The micro-convex portion is a solid substrate having a hydrophilic surface, characterized in that formed by spraying the fine particles on the surface with a particle injector. The method according to claim 11 or 12, The ultra-fine hole is a solid substrate having a hydrophilic surface, characterized in that formed by anodizing. Positioning the spray nozzle of the particle injector opposite the surface of the solid substrate; Driving the particle injector to spray fine particles onto the surface of the solid substrate to form fine roughness to have hydrophilicity; Anodizing the surface of the solid substrate on which the fine irregularities are formed to improve hydrophilicity to form an ultrafine hole having a deeper depth than the diameter; And Coating a portion of the surface of the solid substrate on which the fine iron is formed with a non-wetting material to be hydrophobic Surface processing method of a solid substrate comprising a. The method according to any one of claims 9 to 11, The micro-substrate having a heterogeneous surface, characterized in that the hydrophilic portion is formed in a smaller size than the fine irregularities to improve hydrophilicity, and comprises a very fine hole deeper than the diameter. The method of claim 16, The ultra-fine hole is a solid substrate having a heterogeneous surface, characterized in that formed by anodizing.

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