阅读说明：本技术 一种多尺度结构超疏水性能表面的制备方法 (Preparation method of multi-scale structure super-hydrophobic surface ) 是由 王朝晖 李园 郑腾飞 于 2020-05-19 设计创作，主要内容包括：本发明公开了一种具有多尺度结构的超疏水表面的制备方法,具体制作过程如下：首先在硅基底上利用厚胶光刻的方法制作微米尺度的栅格图形,利用刻蚀方法在硅基底上通过光刻的栅格图形制造沟槽阵列；然后在沟槽阵列上用激光超光微细加工技术制造出更小的纳米尺度的沟槽阵列；之后以带有微纳米结构的硅基底为模具,用热压印的方法翻模制造FEP结构。本发明制备的FEP结构是由带有微纳米结构的硅基底为模具翻模制造的,带有相应的多尺度结构,如附图所示,在应用中表现出超疏水性,并能相比普通微结构的超疏水表面保持更长时间的C-B状态稳定性,从而长时间维持超疏水性能,表现出减阻,自清洁等功能。(The invention discloses a preparation method of a super-hydrophobic surface with a multi-scale structure, which comprises the following specific preparation processes: firstly, manufacturing a micron-scale grid pattern on a silicon substrate by using a thick-film photoetching method, and manufacturing a groove array on the silicon substrate by using the photoetching grid pattern by using an etching method; then, manufacturing a smaller nano-scale groove array on the groove array by using a laser ultra-light micro-machining technology; and then, the FEP structure is manufactured by using a silicon substrate with a micro-nano structure as a mould and performing mould turnover by a hot-stamping method. The FEP structure prepared by the invention is manufactured by using a silicon substrate with a micro-nano structure as a mould through turnover, has a corresponding multi-scale structure, shows super-hydrophobicity in application as shown in the attached drawing, and can keep the stability of a C-B state for a longer time compared with a super-hydrophobic surface of a common microstructure, thereby maintaining the super-hydrophobic performance for a long time, and showing the functions of drag reduction, self-cleaning and the like.)

1. A preparation method of a multi-scale structure super-hydrophobic surface is characterized by comprising the following steps:

step 1, spin-coating a layer of positive photoresist on a silicon wafer substrate, and exposing by using a mask plate with a light-transmitting grid array;

step 2, placing the structure obtained after exposure in the step 1 into a developing solution for development to obtain a silicon wafer substrate with a grid-type convex photoresist array;

step 3, processing the silicon wafer substrate obtained in the step 2 in an oxygen plasma dry photoresist remover to obtain a silicon wafer substrate with photoresist removed completely;

step 4, processing the silicon wafer substrate obtained in the step 3 by using a wet etching method to obtain a silicon wafer substrate with a grid-type convex array;

step 5, treating the silicon wafer substrate obtained in the step 4 with acetone to remove the surface photoresist layer, and depositing a hydrophobic coating C4F8 by using a plasma enhanced chemical vapor deposition PECVD system;

step 6, processing a nano-scale groove array on the pattern area of the silicon chip substrate obtained in the step 5 by using flexible electric plate ultra-light laser manufacturing equipment;

and 7, using the silicon wafer obtained in the step 6 as a die, and performing hot stamping on the pattern on the silicon wafer by turning over the FEP to obtain the super-hydrophobic surface with the multi-scale structure.

2. The method for preparing the multi-scale structure superhydrophobic surface according to claim 1, wherein in step 1, a layer of hexamethyldisilazane HMDS is coated first before coating the photoresist.

3. The method for preparing the superhydrophobic surface with the multi-scale structure according to claim 1, wherein the photoresist in the step 1 is an AZP4620 positive photoresist with a thickness of 8 μm.

4. The method for preparing the multi-scale structure superhydrophobic surface according to claim 1, wherein the width of the grid-type protrusion array obtained in step 2 is 40 μm, and the width of the recessions is 10 μm.

5. The method for preparing the multi-scale structure superhydrophobic surface according to claim 1, wherein step 3 is performed for 5min by using an oxygen plasma dry photoresist remover with 350W working power.

6. The method for preparing the superhydrophobic surface with the multi-scale structure according to claim 1, wherein the depth of the trench etched in the step 4 is 50 μm.

7. The method for preparing the multi-scale structure superhydrophobic surface according to claim 1, wherein the deposition treatment time of C4F8 in step 5 is 90 s.

8. The method for preparing the superhydrophobic surface with the multi-scale structure according to claim 1, wherein the depth of the grooves in the step 6 is 100nm and the width of the grooves is 200 nm.

9. The method for preparing the multi-scale structure superhydrophobic surface according to claim 1, wherein the pressure applied in the hot stamping process in step 7 is 0.018MPa, the processing temperature is 268 ℃, and the processing time is 5 min.

Technical Field

The invention belongs to the technical field of micro-nano manufacturing, and particularly relates to a preparation method of a micro-nano multi-scale structure super-hydrophobic surface.

Background

Due to the potential application of the super-hydrophobic structure in the aspects of surface cleaning, microfluidic systems, biocompatibility and the like, the super-hydrophobic structure becomes one of hot spots of research in recent years. The principle of the super-hydrophobicity of the super-hydrophobic structure is mainly that liquid is in a Cassie-Baxter state on the surface of a microstructure, a gas layer and three interfaces exist between the liquid surface and the solid surface, the apparent contact angle of liquid drops is large, the rolling angle is small, and the liquid drops are easy to roll off from the surface, so that the super-hydrophobic structure has the functions of self-cleaning, drag reduction and the like. However, in a complex water environment, the C-B state is easily destroyed, and the super hydrophobicity of the surface per se and the expressed function are lost.

Disclosure of Invention

The invention aims to provide a preparation method of a super-hydrophobic surface with a multi-scale structure, so as to solve the problems.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a multi-scale structure super-hydrophobic surface comprises the following steps:

step 1, spin-coating a layer of positive photoresist on a silicon wafer substrate, and exposing by using a mask plate with a light-transmitting grid array;

step 2, placing the structure obtained after exposure in the step 1 into a developing solution for development to obtain a silicon wafer substrate with a grid-type convex photoresist array;

step 3, processing the silicon wafer substrate obtained in the step 2 in an oxygen plasma dry photoresist remover to obtain a silicon wafer substrate with photoresist removed completely;

step 4, processing the silicon wafer substrate obtained in the step 3 by using a wet etching method to obtain a silicon wafer substrate with a grid-type convex array;

step 5, treating the silicon wafer substrate obtained in the step 4 with acetone, removing the surface photoresist layer, and depositing a hydrophobic coating C4F8 by using a PECVD system;

step 6, processing a nano-scale groove array on the pattern area of the silicon chip substrate obtained in the step 5 by using flexible electric plate ultra-light laser manufacturing equipment;

and 7, using the silicon wafer obtained in the step 6 as a die, and performing hot stamping on the pattern on the silicon wafer by turning over the FEP to obtain the super-hydrophobic surface with the multi-scale structure.

Further, in the step 1, a layer of HMDS is coated first before the coating is coated on the photoresist.

Further, the photoresist in the step 1 is AZP4620 positive photoresist, and the thickness of the photoresist is 8 μm.

Further, the width of the grid-type protrusion array obtained in step 2 is 40 μm, and the width of the recessions is 10 μm.

Further, step 3 is performed for 5min by using an oxygen plasma dry photoresist remover and working power of 350W.

Further, the depth of the trench etched in step 4 is 50 μm.

Further, the deposition time of C4F8 in step 5 was 90 s.

Further, in the step 6, the depth of the groove of the laser ultra-optical micro-machining is 100nm, and the width of the groove is 200 nm.

Further, in step 7, the applied pressure of the hot stamping process is 0.018MPa, the processing temperature is 268 ℃, and the processing time is 5 min.

Compared with the prior art, the invention has the following technical effects:

in the preparation method, the micro-nano processing method for processing the micro-structure array and the laser super-light micro-machining technology for processing the nano-structure are very mature, so that the difficulty in preparing the multi-scale structure super-hydrophobic surface is reduced, and the realization possibility is improved; because the mask plate in the photoetching process and the die in the hot stamping process can be repeatedly used, the processing cost is reduced, and the possibility is provided for large-scale production; since FEP is a flexible hydrophobic material, the superhydrophobic surface can be applied to structures of various shapes.

The super-hydrophobic surface prepared by the method has a groove structure with two-stage sizes of micron and nanometer, the micron structure ensures that the surface has effective wetting characteristics, and the existence control of the nanometer structure makes wetting transformation more difficult to occur, so that the service life of the super-hydrophobic surface is prolonged.

In conclusion, the invention combines the micro-nano processing technology, the laser ultra-light micro-processing technology and the hot stamping technology to prepare the super-hydrophobic surface with the multi-scale structure, and the multi-scale structure has the functions of prolonging the gas residence time, keeping the stability of the C-B state and prolonging the service life of the super-hydrophobic surface. This is a property not found in previous single-scale superhydrophobic structured surfaces.

Drawings

FIG. 1 is a schematic view of a mask with a grid light-transmitting array used in step 1 of the present invention;

FIG. 2 is a schematic diagram of a detailed light-transmitting structure of a mask with a grid light-transmitting array used in step 1 of the present invention, where the region is a square region in FIG. 1, and black is a light-transmitting region;

FIG. 3 is a schematic cross-sectional view of a silicon wafer with a micro-groove structure, which is etched and processed by removing photoresist in step 3 according to the present invention;

FIG. 4 is a schematic cross-sectional view of a silicon wafer with a nanostructure micro-machined on the surface of the microstructure by an ultra-light laser in step 6 according to the present invention;

FIG. 5 is a schematic cross-sectional view of FEP with multi-scale structure obtained by hot stamping and overmolding in step 7 of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings:

referring to fig. 1 to 5, a method for preparing a multi-scale structured superhydrophobic surface includes the following steps:

step 1, spin-coating a layer of positive photoresist on a silicon wafer substrate, and exposing by using a mask plate with a light-transmitting grid array;

step 2, placing the structure obtained after exposure in the step 1 into a developing solution for development to obtain a silicon wafer substrate with a grid-type convex photoresist array;

step 3, processing the silicon wafer substrate obtained in the step 2 in an oxygen plasma dry photoresist remover to obtain a silicon wafer substrate with photoresist removed completely;

step 4, processing the silicon wafer substrate obtained in the step 3 by using a wet etching method to obtain a silicon wafer substrate with a grid-type convex array;

step 5, treating the silicon wafer substrate obtained in the step 4 with acetone, removing the surface photoresist layer, and depositing a hydrophobic coating C4F8 by using a PECVD system;

step 6, processing a nano-scale groove array on the pattern area of the silicon chip substrate obtained in the step 5 by using flexible electric plate ultra-light laser manufacturing equipment;

and 7, using the silicon wafer obtained in the step 6 as a die, and performing hot stamping on the pattern on the silicon wafer by turning over the FEP to obtain the super-hydrophobic surface with the multi-scale structure.

In the step 1, a layer of HMDS is coated first before the coating is coated on the photoresist.

The photoresist in the step 1 is AZP4620 positive photoresist, and the thickness of the photoresist is 8 μm.

The width of the grid-type convex array obtained in the step 2 is 40 μm, and the width of the concave part is 10 μm.

And 3, processing for 5min by using an oxygen plasma dry photoresist remover at the working power of 350W.

The depth of the trench etched in step 4 is 50 μm.

The C4F8 deposition process time in step 5 was 90 s.

In the step 6, the depth of the groove of the laser ultra-light micro-machining is 100nm, and the width of the groove is 200 nm.

In the step 7, the applied pressure of hot stamping processing is 0.018MPa, the processing temperature is 268 ℃, and the processing time is 5 min.