Wear-resistant transparent super-hydrophobic coating and preparation method thereof

Abstract

The invention discloses a wear-resistant transparent super-hydrophobic coating. The wear-resistant transparent super-hydrophobic coating comprises a transparent super-hydrophobic coating sprayed on the surface of a transparent substrate containing an etching groove, grooves which are uniformly distributed at intervals are formed in the surface of the transparent substrate containing the etching groove; the super-hydrophobic coating is obtained by spraying transparent super-hydrophobic SiO2-based dispersion liquid on the surface of a transparent substrate containing an etching groove, and the transparent super-hydrophobic SiO2-based dispersion liquid contains an alcohol solvent, alkali liquor, a silicon source, a silane coupling agent and a low-surface-energy modifier. According to the method, the surface of the transparent substrate is etched by adopting a laser etching process, and an improved transparent super-hydrophobic SiO2-based dispersion liquid and a spraying process are combined, so that the super-hydrophobic coating with good adhesion performance, wear resistance, hydrophobic performance and anti-reflection performance is constructed on the surface of the transparent substrate; the method can be applied to the fields of automobile glass, textile fabrics, oil-water separation, electronic communication and the like; and the related preparation process is simple, the reaction condition is mild, the method is environment-friendly, and large-scale popularization and application can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional materials, and in particular relates to a wear-resistant transparent super-hydrophobic coating and a preparation method thereof. Background Art

[0002] Superhydrophobic surfaces have the ability to stay dry, self-clean, and avoid biological contamination, and have good application prospects in biotechnology, medicine, and heat transfer. However, the rough surface of superhydrophobic surfaces usually only has a small part in contact with the liquid, which will be subjected to high local pressure under mechanical load and is prone to wear. In addition, wear exposes the underlying material and may change the local properties of the surface from hydrophobic to hydrophilic, resulting in problems such as failure of hydrophobic properties. In the specific application process, it is necessary to take into account good water resistance and wear resistance.

[0003] In the fields of automobiles and photovoltaic power generation, while emphasizing the protective performance of the coating surface, higher requirements are gradually being placed on its transparency. For example, in the fields of automobile manufacturing, super-hydrophobic coatings can be used to manufacture automobile windshields, and the coating must have high transparency and durability to resist the erosion of rain and stains, and keep the windshield clean and clear of sight; in the fields of photovoltaic power generation, since photovoltaic cells need to be exposed to sunlight to generate electricity, the coating must have high transparency to ensure that sunlight can penetrate the coating and shine on the surface of the photovoltaic cells. At the same time, it is also necessary to have excellent super-hydrophobicity to prevent dust, water droplets and other pollutants from adhering to the surface of the photovoltaic cells and affecting the photoelectric conversion efficiency; in the fields of optical components, the coating must have high transparency to ensure that the light transmission performance of the optical components is not affected, and it is also necessary to have excellent super-hydrophobicity and durability to prevent stains, grease and other pollutants from adhering to the surface of the optical components and affecting the imaging quality.

[0004] However, existing transparent super-hydrophobic systems usually have problems such as poor mechanical wear resistance, low visible light transmittance, high preparation cost and complex preparation methods. Conventional means of improving mechanical strength usually require increasing the thickness of the film or changing its constituent materials, which will affect and reduce the transmittance to a certain extent. On the other hand, optimizing the microstructure of the film to improve the transmittance may have a certain impact on its mechanical strength. Therefore, while maintaining transparency and super-hydrophobic properties, taking into account good mechanical wear resistance is a challenging problem. Summary of the invention

[0005] The main purpose of the present invention is to provide a super hydrophobic transparent coating with good light transmittance, hydrophobicity and wear resistance in order to address the deficiencies in the prior art. The preparation process involved is simple, the reaction conditions are mild, and the coating is environmentally friendly, so it can be promoted and applied on a large scale.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A wear-resistant transparent super-hydrophobic coating comprises a transparent super-hydrophobic coating sprayed on the surface of a transparent substrate containing etching grooves.

[0008] Furthermore, the surface of the transparent substrate containing the etched grooves is provided with grooves arranged evenly and spaced apart, the groove width is 10 to 50 μm, the depth is 15 to 50 μm, and the spacing between two adjacent grooves is 3 to 20 μm.

[0009] Furthermore, the etched grooves are obtained by etching on the surface of the transparent substrate using a femtosecond laser process.

[0010] Furthermore, the transparent substrate may be made of transparent glass, transparent plastic or transparent ceramic.

[0011] In the above scheme, the super hydrophobic coating is obtained by spraying a transparent super hydrophobic SiO2-based dispersion on the surface of a transparent substrate containing an etched groove, and then drying.

[0012] In the above scheme, the transparent super-hydrophobic SiO2-based dispersion contains an alcohol solvent, an alkali solution, a silicon source, a silane coupling agent and a low surface energy modifier.

[0013] In the above scheme, the components and their volume fractions in the transparent superhydrophobic SiO2-based dispersion include: 80-100 parts of alcohol solvent, 0.1-2 parts of alkali solution, 0.4-4 parts of silicon source, 1-4 parts of silane coupling agent, and 0.1-4 parts of low surface energy modifier.

[0014] In the above scheme, the alcohol solvent can be selected from one or more of ethanol, methanol, isopropanol and the like.

[0015] In the above scheme, the alkali solution is NaOH solution, KOH solution or ammonia solution, wherein the concentration of NaOH solution and KOH solution is 1-1.8 mol / L, and the concentration of ammonia solution is 25-29 wt%.

[0016] In the above scheme, the silicon source is one or more of tetraethyl orthosilicate, tetrabutyl orthosilicate, propyl silicate or butyl silicate, and hydrophilic fumed silica particles.

[0017] In the above scheme, the silane-based low surface energy substance is one or more of hexamethyldisilazane, methyltriethoxysilane, hexadecyltrimethoxysilane, and perfluorodecyltrimethoxysilane.

[0018] In the above scheme, the silane coupling agent is one or more of KH550, KH560, KH570 and the like.

[0019] The above-mentioned method for preparing a wear-resistant transparent super-hydrophobic coating comprises the following steps:

[0020] (1) adding alkali solution, silane coupling agent and silicon source into an alcohol solvent and performing ultrasonic stirring to obtain a uniformly dispersed transparent hydrophilic SiO2 dispersion;

[0021] (2) adding a low surface energy modifier to the transparent hydrophilic SiO2 dispersion obtained in step (1), stirring and reacting to obtain a transparent super-hydrophobic SiO2-based dispersion;

[0022] (3) cleaning the transparent substrate, and then etching the surface thereof using a femtosecond laser process to obtain a transparent substrate containing etching grooves;

[0023] (4) Spraying the obtained super-hydrophobic SiO2-based dispersion onto the surface of the transparent substrate containing the etched grooves and drying the dispersion to obtain the wear-resistant transparent super-hydrophobic coating.

[0024] In the above scheme, during the preparation process of steps (1) to (2), the ambient temperature is room temperature.

[0025] In the above scheme, the stirring time in step (1) is 10 to 30 minutes.

[0026] In the above scheme, in step (2), the volume ratio of the transparent hydrophilic SiO2 dispersion to the low surface energy substance is 100:(0.1~1).

[0027] In the above scheme, the stirring reaction time of step (2) is 6 to 12 hours, and the stirring rate is 600 to 800 rpm / min.

[0028] In the above scheme, in step (3), the transparent substrate is washed with ethanol and deionized water in sequence, and then etched with a femtosecond ultraviolet laser etcher.

[0029] In the above scheme, the parameters of the femtosecond laser process include: laser spot size of 8-10um, wavelength of 343-350nm, power of 6-6.5w, pulse width less than 350fs, frequency of 1k-2mHz, and scanning speed of 1000-1200mm / s.

[0030] Furthermore, the spraying conditions include: the spray gun caliber is 0.8-1.0 mm, the air pressure is 0.4-0.7 MPa; the spraying angle is perpendicular to the substrate; the spraying distance is 25-30 cm; and the spray width is 10-15 cm.

[0031] According to the above scheme, a super-hydrophobic coating with good bonding performance, wear resistance and light transmittance can be constructed on the surface of a transparent substrate; the average transmittance in the visible light range (380-800nm) can reach more than 82.5%, the water contact angle can reach more than 163°, and it has excellent wear resistance and can maintain good long-term hydrophobic performance. The wear-resistant transparent super-hydrophobic coating is expected to be applied to the fields of automobile manufacturing, photovoltaic power generation, optical components, building materials, etc.

[0032] The principle of the present invention is:

[0033] The present invention adopts a laser etching process to perform etching treatment on the surface of a transparent substrate, and combines a transparent super-hydrophobic SiO2-based dispersion and a spraying process to construct a super-hydrophobic coating with good adhesion performance, wear resistance, hydrophobicity and anti-transmittance performance on the surface of the transparent substrate: by optimizing the transparent super-hydrophobic dispersion, good super-hydrophobic performance and visible light transmittance can be taken into account; at the same time, the width, depth and spacing of the obtained etching grooves are regulated by a femtosecond laser process and combined with a spraying process, which can promote the effective combination of functional particles in the transparent super-hydrophobic dispersion and the transparent substrate, and can reduce the refraction and reflection of light to a certain extent, increase the transmittance of visible light, and finally form a super-hydrophobic coating with good bonding performance, wear resistance and visible light transmittance on the surface of the transparent substrate.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1) The present invention optimizes the formula of the super-hydrophobic SiO2-based dispersion to achieve both good super-hydrophobic performance and visible light transmittance;

[0036] 2) The present invention combines a transparent super-hydrophobic dispersion with a transparent substrate containing etched grooves and a spraying process, which can significantly improve the wear resistance of the resulting coating, while taking into account good super-hydrophobic and light-transmitting properties, and can achieve an anti-reflection effect to a certain extent, which can provide a new idea for the preparation of high-performance transparent super-hydrophobic coatings;

[0037] 3) The preparation method of the present invention is simple, the reaction conditions are mild, the cost is low, and it can be produced in large quantities. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a morphology photo of the sample obtained in Example 1 after water drops were added to the surface;

[0039] Figure 2 This is a photo of the water contact angle of the sample surface obtained in Example 1;

[0040] Figure 3 The light transmittance test results of the glass substrate with etched grooves obtained in Example 1 before and after spraying;

[0041] Figure 4This is a morphology photograph of the sample obtained in Example 2 after water drops were added to the surface;

[0042] Figure 5 This is a photo of the water contact angle of the sample surface obtained in Example 2;

[0043] Figure 6 The light transmittance test results of the glass substrate with etched grooves obtained in Example 2 before and after spraying;

[0044] Figure 7 This is a morphology photograph of the sample obtained in Example 3 after water drops were added to the surface;

[0045] Figure 8 This is a photo of the water contact angle of the sample surface obtained in Example 3;

[0046] Fig. 9 This is a morphological photograph of the sample obtained in Example 3 after oil drops were added to the surface;

[0047] Fig.10 This is a photo of the oil contact angle of the sample surface obtained in Example 3;

[0048] Fig.11 The test results of friction cycle and water contact angle of the sample obtained in Example 3 and the sample obtained by spraying with unetched glass;

[0049] Fig.12 The test results of friction cycle and oil contact angle of the sample obtained in Example 3 and the sample obtained by spraying with unetched glass;

[0050] Fig.13 The following are scanning electron microscope (SEM) images of samples obtained at different stages and samples obtained under different friction test conditions in Example 3;

[0051] Fig.14 The light transmittance test results of the glass substrate containing etched grooves obtained in Example 3 before and after spraying are shown. DETAILED DESCRIPTION

[0052] The applicant will further explain the present invention in detail below in conjunction with specific embodiments so that those skilled in the art can more clearly understand the present invention. However, the following content should not be construed as limiting the scope of protection of the claims of the present invention.

[0053] The chemical reagents and solvents used in the examples are all analytically pure. The stirring is carried out using a magnetic stirrer.

[0054] In the following examples, the silane coupling agent used is KH550.

[0055] Example 1

[0056] A wear-resistant transparent super-hydrophobic coating, the preparation method of which comprises the following steps:

[0057] (1) Under magnetic stirring at room temperature, add 0.3 ml of 1.8 M NaOH solution to 100 ml of ethanol, add 1 ml of KH550, stir at 600 rpm / min for 10 min, then slowly add 3 ml of tetraethyl orthosilicate, and hydrolyze at room temperature for 12 h to obtain a silicon dispersion;

[0058] (2) 3 ml of hexamethyldisilazane was uniformly dispersed in the silicon dispersion obtained in step (1), and then stirred (magnetic stirring) at a speed of 600 rpm / min for 12 hours to obtain a transparent, super-hydrophobic dispersion;

[0059] (3) The glass slide was washed with ethanol and deionized water in turn, and its surface was etched by a laser etcher, wherein the laser etcher was a femtosecond ultraviolet laser etcher YLET3030UF, the light spot was set to 8um, the power was 6.5w, the wavelength was 350nm, the frequency was 2kHz, the pulse width was less than 350fs, and the scanning speed was 1200mm / s, to obtain a glass substrate with uniform and spaced etched grooves; wherein the grooves had a width of 15um, a depth of 20um, and a spacing of 10um;

[0060] (4) Preparation of a transparent super-hydrophobic glass coating: The transparent, super-hydrophobic dispersion is evenly sprayed on the glass substrate obtained in step (3) by spraying. The super-hydrophobic dispersion is shaken up and down for about 5 minutes before spraying. When pouring the super-hydrophobic dispersion into the spray gun, it is filtered through a 100-mesh filter cloth. The spraying conditions used include: using an Iwata W-71 air spray gun (caliber 0.8 mm), air pressure: 0.4 MPa; spraying angle: perpendicular to the substrate; spraying distance: 25 cm; spray width: 10 cm; spraying 2 times (actual dry thickness 20 μm ± 5 μm); after the paint film is completely dry (about 10 minutes), the wear-resistant transparent super-hydrophobic coating is formed on the etched glass substrate surface.

[0061] Figure 1 Schematic diagram of the hydrophobic effect of the transparent super-hydrophobic coating obtained in this embodiment, wherein water droplets can gather into small balls on the surface of the transparent super-hydrophobic coating, and have good hydrophobic properties. Figure 2 This is a photograph of the water contact angle of the transparent super-hydrophobic coating obtained in this example, wherein the contact angle is 163.5°, which has excellent super-hydrophobic properties.

[0062] The obtained super-hydrophobic coating (including glass substrate) was placed on sandpaper (2000 mesh), and a wear resistance test was carried out using a 50g weight with a horizontal movement of 10cm as one cycle. The results showed that the water contact angle after 25 cycles was 145.1°, the water contact angle after 35 cycles was 122.3°, and the water contact angle after 45 cycles was 90.5°; this embodiment has good bonding performance with the glass substrate, and the obtained transparent super-hydrophobic coating can ensure good wear resistance and a relatively stable hydrophobic effect.

[0063] Figure 3 This is the transmittance (light transmittance) test result of the transparent super-hydrophobic coating obtained in this embodiment. By comparing the transmittance changes of the glass samples before and after spraying, it can be seen that the coating set by the method described in the present invention can further exhibit excellent anti-reflection effect; the obtained glass + transparent super-hydrophobic coating product has an average transmittance of 84.7% in the visible light range (the average transmittance of the glass substrate in the visible light range is 80.5%), which has a good anti-reflection effect.

[0064] Example 2

[0065] A wear-resistant transparent super-hydrophobic coating, the preparation method of which comprises the following steps:

[0066] (1) Under magnetic stirring at room temperature, add 2 ml of ammonia solution (25 wt%) to 100 ml of ethanol, add 1 ml of KH550, stir at 600 rpm / min for 10 min, then slowly add 4 ml of tetraethyl orthosilicate, hydrolyze at room temperature for 12 h to obtain a silicon dispersion, and let it stand for 3 days;

[0067] (2) 4 ml of hexamethyldisilazane was uniformly dispersed in the silicon dispersion obtained in step (1), and then stirred (magnetically stirred) at a speed of 600 rpm / min for 12 h to obtain a transparent, super-hydrophobic dispersion;

[0068] (3) The glass slide was washed with ethanol and deionized water in turn, and its surface was etched by a laser etcher, wherein the laser etcher was a femtosecond ultraviolet laser etcher YLET3030UF, and the light spot was set to 8um, the power was 6w, the wavelength was 343nm, the frequency was 1kHz, the pulse width was less than 350fs, and the scanning speed was 1000mm / s, to obtain a glass substrate with uniform and spaced etched grooves; wherein the grooves had a width of 20um, a depth of 25um, and a spacing of 12um;

[0069] (4) Preparation of transparent super-hydrophobic glass coating: The super-hydrophobic dispersion was shaken up and down for about 5 minutes before spraying, and was filtered through a 100-mesh filter cloth before pouring into the spray gun; the spraying conditions used included: using an Iwata W-71 air spray gun (caliber 1.0 mm), air pressure: 0.7 MPa; spraying angle: perpendicular to the substrate; spraying distance: 30 cm; spray width: 15 cm; spraying 2 times (the actual dry thickness of the topcoat was 20 μm ± 5 μm); after drying, the wear-resistant transparent super-hydrophobic coating was formed on the etched glass substrate surface.

[0070] Figure 4 Schematic diagram of the hydrophobic effect of the product obtained in this example, wherein water droplets can gather into small balls on the surface of the obtained super-hydrophobic coating, and have good hydrophobic properties. Figure 5 This is a photo of the water contact angle of the obtained coating sample, where the water contact angle is 164.4°, and the surface has excellent superhydrophobic properties.

[0071] Referring to the wear resistance test method described in Example 1, the results show that the super-hydrophobic coating (containing a glass substrate) obtained in this example has a contact angle of 140.1° after 30 cycles, a contact angle of 112.3° after 35 cycles, and a contact angle of 87.6° after 40 cycles.

[0072] Figure 6 The transmittance test results of the obtained product are compared. By comparing the transmittance changes of the glass samples before and after spraying, it can be seen that the coating sample system obtained by the present invention can further exhibit excellent anti-reflection effect. The average transmittance of the obtained glass + transparent super-hydrophobic coating product in the visible light range can reach 82.5% (the average transmittance of the glass substrate in the visible light range is 77.5%).

[0073] Example 3

[0074] A wear-resistant transparent super-hydrophobic coating, the preparation method of which comprises the following steps:

[0075] (1) Under magnetic stirring at room temperature, 0.7 ml of 1.8 M NaOH solution, 1 ml of KH550, and then 1 g of hydrophilic fumed silica with an average particle size of 15 nm were added to 100 ml of ethanol, and the mixture was stirred at 600 rpm / min for 30 min, and then ultrasonicated for 30 min to obtain a silicon dispersion;

[0076] (2) 5 ml of water and 0.35 ml of perfluorodecyltrimethoxysilane were uniformly dispersed in the silicon dispersion obtained in step (1), and then stirred (magnetic stirring) at a speed of 600 rpm / min for 12 hours to obtain a transparent, super-amphiphobic dispersion;

[0077] (3) The glass slide was washed with ethanol and deionized water in turn, and its surface was etched by a laser etcher, wherein the laser etcher was a femtosecond ultraviolet laser etcher YLET3030UF, the light spot was set to 10 μm, the power was 6.5 W, the wavelength was 343 nm, the frequency was 1 kHz, the pulse width was less than 350 fs, and the scanning speed was 200 mm / s, to obtain a glass slide substrate containing uniform and spaced etched grooves, wherein the grooves had a width of 10 μm, a depth of 15 μm, and a spacing of 3 μm;

[0078] (4) Preparation of transparent super-hydrophobic glass coating: The super-amphiphobic dispersion was shaken up and down for about 5 minutes before spraying, and was filtered through a 100-mesh filter cloth before pouring into the spray gun; the spraying conditions used included: using an Iwata W-71 air spray gun (caliber 0.8 mm), air pressure: 0.5 MPa; spraying angle: perpendicular to the substrate; spraying distance: 30 cm; spray width: 15 cm. Spray twice (the actual dry thickness of the topcoat is 20 μm ± 5 μm); after drying, the wear-resistant transparent super-hydrophobic coating was formed on the surface of the etched glass slide substrate.

[0079] Figure 7 Schematic diagram of the hydrophobic effect of the product obtained in this example, wherein water droplets can gather into small balls on the surface of the coating, which has good hydrophobic properties. Figure 8 This is a contact angle photograph of the coating sample obtained in this example, wherein the contact angle of water is 169.6°, which has good superhydrophobic properties.

[0080] Fig. 9 Schematic diagram of the oleophobic effect of the coating sample obtained in this example, wherein the oil droplets can gather into small balls on the surface of the obtained coating, and have good oleophobic properties.

[0081] Fig.10 This is a photograph of the oil contact angle of the coating sample obtained in this example, wherein the oil contact angle is 155.5°, which has good oleophobic properties.

[0082] Fig.11 The photos of the friction cycle and water contact angle of the obtained coating sample and the friction cycle and water contact angle of the unetched glass show that the sample etched by laser has excellent wear resistance compared with the unetched glass, and can ensure more stable hydrophobic performance.

[0083] Fig.12 The photos of the friction cycle and oil contact angle of the obtained coating sample and the friction cycle and water contact angle of the unetched glass show that the sample etched by laser has excellent wear resistance compared with the unetched glass, which can ensure a more stable oleophobic performance.

[0084] Fig.13Figure 3 is the SEM images of the glass substrate obtained at different stages, including the glass substrate after laser etching, the grooved glass substrate after spraying the superhydrophobic coating, and the SEM photos after 50 and 100 cycles of friction, respectively. It can be seen that: the protruding part corresponding to the etched groove gradually changes from the initial 3um to 7um after 50 friction cycles and 11um after 100 cycles, and the groove part gradually changes from the initial 10um to 6um after 50 friction cycles and 2um after 100 friction cycles; the designed protruding part can play a better protective role on the performance of the obtained coating (friction cycle: using 2000 mesh sandpaper, a weight of 50g is pressed on the V-shaped glass groove, and moving 10cm is one cycle).

[0085] Fig.14 The transmittance test results of the obtained product are compared. By comparing the transmittance changes of the glass samples before and after spraying, it can be seen that the coating sample system obtained by the present invention can further exhibit excellent anti-reflection effect. The average transmittance of the obtained glass + transparent super-hydrophobic coating product in the visible light range can reach 87.9% (the average transmittance of the glass substrate in the visible light range is 83.5%).

[0086] Comparative Example 1

[0087] A transparent coating based on laser etching of a glass substrate, the preparation method of which comprises the following steps:

[0088] (1) Under the condition of magnetic stirring at room temperature, 2 ml of ammonia solution (25 wt%) was added to 100 ml of ethanol, and 4 ml of tetraethyl orthosilicate was slowly added after stirring at a speed of 600 rpm / min for 10 min. The solution was hydrolyzed at room temperature for 12 h to obtain a silicon dispersion, which was then allowed to stand for 3 days;

[0089] (2) 4 ml of hexamethyldisilazane was uniformly dispersed in the silicon dispersion obtained in step (1), and then stirred (magnetically stirred) at a speed of 600 rpm / min for 12 h to obtain a transparent, super-hydrophobic dispersion;

[0090] (3) The glass slide was washed with ethanol and deionized water in turn, and its surface was etched by a laser etcher, wherein the laser etcher was a femtosecond ultraviolet laser etcher YLET3030UF, and the light spot was set to 8um, the power was 6w, the wavelength was 343nm, the frequency was 1kHz, the pulse width was less than 350fs, and the scanning speed was 1000mm / s, to obtain a glass substrate with uniform and spaced etched grooves; wherein the grooves had a width of 20um, a depth of 25um, and a spacing of 12um;

[0091] (4) Preparation of transparent super-hydrophobic glass coating: The transparent super-hydrophobic dispersion is sprayed evenly on the glass substrate obtained in step (3) by spraying. The super-hydrophobic dispersion is shaken up and down for about 5 minutes before spraying. When pouring into the spray gun, it is filtered through a 100-mesh filter cloth; the spraying conditions used include: using an Iwata W-71 air spray gun (caliber 1.0 mm), air pressure: 0.7 MPa; spraying angle: perpendicular to the substrate; spraying distance: 30 cm; spray width: 15 cm; spraying 2 times (the actual dry thickness of the topcoat is 20 μm ± 5 μm); after it is actually dried, the wear-resistant transparent super-hydrophobic coating is formed on the surface of the etched glass substrate. 。

[0092] The test results show that the hydrophobic angle of the coating (with glass substrate) prepared in the comparative example is 152.3°, and the average transmittance in the visible light range is 81.2%, which is lower than the transmittance of the glass substrate.

[0093] Referring to the wear resistance test method described in Example 1, the results show that the super-hydrophobic coating (containing a glass substrate) obtained in this comparative example has a contact angle of 140.1° after 10 cycles, a contact angle of 112.3° after 15 cycles, and a contact angle of 79.2° after 25 cycles.

[0094] Comparative Example 2

[0095] A transparent coating based on a laser-etched glass substrate, the preparation method of which comprises the following steps:

[0096] (1) Under magnetic stirring at room temperature, 0.7 ml of 1.8 M NaOH solution, 1 ml of KH550, and then 1 g of hydrophilic fumed silica with an average particle size of 15 nm were added to 100 ml of ethanol, and the mixture was stirred at 600 rpm / min for 30 min, and then ultrasonicated for 30 min to obtain a silicon dispersion;

[0097] (2) 5 ml of deionized water and 0.35 ml of perfluorodecyltrimethoxysilane were uniformly dispersed in the silicon dispersion obtained in step (1), and then stirred (magnetic stirring) at a speed of 600 rpm / min for 12 hours to obtain a transparent, super-amphiphobic dispersion;

[0098] (3) The glass slide was washed with ethanol and deionized water in turn, and its surface was etched by a laser etcher, wherein the laser etcher was a femtosecond ultraviolet laser etcher YLET3030UF, the light spot was set to 10 μm, the power was 6.5 W, the wavelength was 343 nm, the frequency was 1 kHz, the pulse width was less than 350 fs, and the scanning speed was 200 mm / s, to obtain a glass slide substrate containing uniform and spaced etched grooves, wherein the grooves had a width of 10 μm, a depth of 15 μm, and a spacing of 3 μm;

[0099] (4) Using a spin coater (model: KW-4A / 5 type coating machine), the transparent, super-amphiphobic dispersion obtained in step (2) is spin-coated on the surface of the substrate obtained in step (3), and the speed of gear I is set to 500 rpm / min, the time is 15 s, and the speed of gear II is set to 1000 rpm / min, the time is 30 s, to obtain a transparent coating based on the laser-etched glass substrate.

[0100] The test results show that the coating prepared in the comparative example has a hydrophobic angle of 153.7°, an oleophobic angle of 112.5°, and an average transmittance of 79.7% in the visible light range.

[0101] Referring to the wear resistance test method described in Example 1, the results show that the super hydrophobic coating (containing a glass substrate) obtained in this comparative example has a water contact angle of 132.1° after 10 cycles, a water contact angle of 100.3° after 15 cycles, and a water contact angle of 85.2° after 20 cycles.

[0102] Comparative Example 3

[0103] A transparent coating based on a laser-etched glass substrate, the preparation method of which comprises the following steps:

[0104] (1) Under magnetic stirring at room temperature, add 0.7 ml of 1.8 M NaOH solution, 1 ml of KH550, and 1 g of hydrophilic fumed silica with an average particle size of 15 nm to 100 ml of ethanol, stir for 30 min, and then ultrasonicate for 30 min to obtain a silicon dispersion;

[0105] (2) 3 ml of hexamethyldisilazane was uniformly dispersed in the silicon dispersion obtained in step (1), and then stirred (magnetic stirring) at a speed of 600 rpm / min for 12 hours to obtain a transparent, super-hydrophobic dispersion;

[0106] (3) The glass slide was washed with ethanol and deionized water in turn, and its surface was etched by a laser etcher, wherein the laser etcher was a femtosecond ultraviolet laser etcher YLET3030UF, and the light spot was set to 10 μm, the power was 6.5 W, the wavelength was 345 nm, the frequency was 1 kHz, the pulse width was less than 350 fs, and the scanning speed was 300 mm / s, to obtain a glass slide substrate containing uniform and spaced etched grooves, wherein the grooves had a width of 100 μm, a depth of 80 μm, and a spacing of 10 μm;

[0107] (4) Preparation of a transparent super-hydrophobic glass coating: The transparent, super-hydrophobic dispersion is evenly sprayed on the glass substrate obtained in step (3) by spraying. The super-hydrophobic dispersion is shaken up and down for about 5 minutes before spraying. When pouring the super-hydrophobic dispersion into the spray gun, it is filtered through a 100-mesh filter cloth. The spraying conditions used include: using an Iwata W-71 air spray gun (caliber 0.8 mm), air pressure: 0.4 MPa; spraying angle: perpendicular to the substrate; spraying distance: 25 cm; spray width: 10 cm; spraying 2 times (actual dry thickness 20 μm ± 5 μm); after the paint film is completely dry (about 10 minutes), the wear-resistant transparent super-hydrophobic coating is formed on the etched glass substrate surface.

[0108] The test results show that the hydrophobic angle of the coating prepared in the comparative example is 158.6°, and the average transmittance of the obtained sample (with substrate) in the visible light range is 78.6%. Referring to the wear test method described in Example 1, the results show that the super hydrophobic coating (containing glass substrate) obtained in this comparative example has a water contact angle of 138.3° after 5 cycles, a water contact angle of 106.3° after 10 cycles, and a water contact angle of 81.2° after 15 cycles.

[0109] The present invention is not limited to the above-mentioned embodiments. For those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention. Contents not described in detail in this specification.

Claims

1. A wear-resistant transparent super-hydrophobic coating, characterized in that: The method comprises spraying a transparent super-hydrophobic coating on the surface of a transparent substrate containing etching grooves.

2. The wear-resistant transparent super-hydrophobic coating according to claim 1, characterized in that: The surface of the transparent substrate containing the etching grooves is provided with grooves arranged evenly and at intervals, the groove width is 10-50 μm, the depth is 15-50 μm, and the spacing between two adjacent grooves is 3-20 μm.

3. The wear-resistant transparent super-hydrophobic coating according to claim 1, characterized in that: The etched groove is obtained by etching on the surface of the transparent substrate using a femtosecond laser process.

4. The wear-resistant transparent super-hydrophobic coating according to claim 1, characterized in that: The transparent substrate is transparent glass, plastic or ceramic.

5. The wear-resistant transparent super-hydrophobic coating according to claim 1, characterized in that: The super hydrophobic coating is obtained by spraying a transparent super hydrophobic SiO2-based dispersion on the surface of a transparent substrate containing etching grooves and drying the resulting coating.

6. The wear-resistant transparent super-hydrophobic coating according to claim 5, characterized in that: The transparent super-hydrophobic SiO2-based dispersion contains an alcohol solvent, an alkali solution, a silicon source, a silane coupling agent and a low surface energy modifier.

7. The wear-resistant transparent super-hydrophobic coating according to claim 6, characterized in that: In the transparent super-hydrophobic SiO2-based dispersion, the components and their volume fractions include: 80-100 parts of alcohol solvent, 0.1-2 parts of alkali solution, 0.4-4 parts of silicon source, 1-4 parts of silane coupling agent, and 0.1-4 parts of low surface energy modifier.

8. The method for preparing the wear-resistant transparent super-hydrophobic coating according to any one of claims 1 to 7, characterized in that: The steps include: (1) adding alkali solution, silane coupling agent and silicon source into an alcohol solvent and performing ultrasonic stirring to obtain a uniformly dispersed transparent hydrophilic SiO2 dispersion; (2) adding a low surface energy modifier to the transparent hydrophilic SiO2 dispersion obtained in step (1), stirring and reacting to obtain a transparent super-hydrophobic SiO2-based dispersion; (3) cleaning the transparent substrate, and then etching the surface thereof using a femtosecond laser process to obtain a transparent substrate containing etching grooves; (4) spraying the obtained transparent super-hydrophobic SiO2-based dispersion onto the surface of the transparent substrate containing the etched grooves and drying the dispersion to obtain the wear-resistant transparent super-hydrophobic coating.

9. The preparation method according to claim 8, characterized in that: The parameters of the femtosecond laser process include: laser spot size of 8-10um, wavelength of 343-350nm, power of 6-6.5w, pulse width less than 350fs, frequency of 1k-2mHz, and scanning speed of 1000-1200mm / s.

10. Application of the wear-resistant transparent super-hydrophobic coating according to claim 1.

Images