High-temperature-resistant super-hydrophobic composite coating as well as preparation method and application thereof

Abstract

The invention relates to a high-temperature-resistant super-hydrophobic carbon fiber / silicon resin composite coating as well as a preparation method and application thereof, and belongs to the technical field of super-hydrophobic coating materials. An air spraying or brush coating method is used for preparing the high-temperature-resistant super-hydrophobic composite coating with carbon fibers as a framework and silicon resin as a low-surface-energy material. The micron carbon fiber skeleton and the nano silicon resin form a structure with rough morphology and low surface energy, so that the super-hydrophobic effect is achieved. By introducing the carbon fiber skeleton and the inorganic filler in the silicon resin, the temperature resistance of the coating is improved, the super-hydrophobic performance can still be kept in the high-temperature environment of 400 DEG C or above, and the coating has wide application prospects in the high-temperature environment and can be applied to the fields of self-cleaning, fog prevention, icing prevention, resistance reduction and the like.

Description

Technical Field

[0001] The invention relates to a high-temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating and a preparation method and application thereof, belonging to the technical field of super-hydrophobic coating materials. Background Art

[0002] Superhydrophobicity is a very common phenomenon in nature. For example, lotus leaves, cicada wings, goose feathers, water strider legs, water spider abdomens, etc. all have superhydrophobic functions. In general, the water contact angle of superhydrophobic materials needs to be greater than 150°, and the rolling angle needs to be less than 10°. So far, researchers have constructed various superhydrophobic surfaces based on bionic theory to achieve self-cleaning, anti-fog, anti-icing, drag reduction and other functions. The preparation of superhydrophobic materials usually needs to meet two aspects: one is that the surface has a rough structure, which can be constructed by spraying, etching, deposition and other methods; the other is that it has low surface energy, which is usually achieved by surface modification of the rough structure using organic materials. Since organic materials decompose at high temperatures, it is difficult for current superhydrophobic coatings to maintain their superhydrophobic properties at high temperatures. This seriously restricts the practical application of superhydrophobic coatings in high temperature environments.

[0003] At present, fluorosilane-modified nanoparticles are the most widely used method for preparing super-hydrophobic coatings. However, the fluorosilane monolayer on the surface of the nanoparticles will decompose at around 200°C. In addition, after the decomposition of the monolayer of fluorosilane, a high-energy surface is exposed, causing the coating to change from super-hydrophobic to super-hydrophilic. At present, there are few studies on high-temperature resistant super-hydrophobic coatings, and there are disadvantages of low tolerance temperature and short temperature resistance time. However, the local temperature of the surface of aircraft, ships, etc. can reach above 400°C, and the existing technology cannot meet their needs. Therefore, it is urgent to develop a super-hydrophobic coating that can withstand ultra-high temperatures and serve for a long time.

[0004] Based on this, the present invention provides a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating. A carbon fiber skeleton is introduced into the coating to improve the temperature resistance, and an inorganic filler is added to the silicone resin to inhibit its decomposition at high temperatures. The coating is provided with a rough structure by a micron carbon fiber skeleton and a nano silicone resin, and the silicone resin provides a low surface energy modification. The super hydrophobic coating of the present invention can still maintain super hydrophobic properties at 500 ° C. The present invention has simple process, low cost, can be constructed over a large area, and has broad application prospects under high temperature use environments. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating and a preparation method and application thereof. The method has simple process, low cost and can be constructed over a large area.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows.

[0007] A method for preparing a high temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating, the method steps comprising:

[0008] Carbon fiber, silicone resin containing inorganic filler, and a binder are mixed in water, and a carbon fiber / silicone resin dispersion is obtained after ultrasonic dispersion; the dispersion is deposited on a substrate by air spraying or brushing, and a carbon fiber / silicone resin composite coating is obtained after solidification; and the carbon fiber / silicone resin composite coating is heat-treated to obtain a carbon fiber / silicone resin composite super-hydrophobic coating containing a nanostructure.

[0009] Preferably, the carbon fiber has a diameter of 1 nm to 20 μm and a length of 10 nm to 10 mm.

[0010] Preferably, the inorganic filler includes one or more of metals, oxides, nitrides, carbides, sulfides, silicides, halides, hydroxides and carbon materials.

[0011] Preferably, the inorganic filler accounts for 0.1 to 50% by mass of the silicone resin.

[0012] Preferably, the silicone resin accounts for 0.1-500% of the carbon fiber mass.

[0013] Preferably, the binder is a water-based binder, including one or more of silicone resin emulsion, polyurethane emulsion, epoxy resin emulsion, polyimide emulsion, vinyl acetate emulsion, acrylic emulsion, polyvinyl acetate emulsion, polyvinyl alcohol, aluminum dihydrogen phosphate, potassium silicate and silica sol.

[0014] Preferably, the amount of the binder used is 0.5 to 500% of the mass fraction of the carbon fibers.

[0015] Preferably, the ultrasonic dispersion refers to ultrasonic dispersion using an ultrasonic cleaning machine or an ultrasonic cell crusher, with a power of 20 to 1000 W and a time of 1 to 30 min.

[0016] Preferably, the matrix includes metal, ceramic, organic matter, carbon material and composite material.

[0017] Preferably, the curing process is carried out in an oven, the curing temperature is from room temperature to 300° C., and the time is 30 min to 5 h.

[0018] Preferably, the heat treatment refers to high temperature treatment in a muffle furnace or flame treatment using a flame spray gun, the temperature is preferably 500 to 2000° C., and the time is preferably 20 seconds to 2 hours.

[0019] Preferably, the nanostructure refers to hydrophobic nano-scale oligomers (oligomer size is 10-200 nm) generated by depolymerization of silicone resin at high temperature.

[0020] Beneficial Effects

[0021] (1) The present invention provides a method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating, wherein a micron carbon fiber skeleton and a nano silicone resin provide a rough structure, and a silicone resin provides a low surface energy modification to achieve a super hydrophobic function (a water contact angle is greater than 150° and a rolling angle is less than 10°). A carbon fiber skeleton is introduced into the coating to improve temperature resistance, and an inorganic filler is added to the silicone resin to inhibit its decomposition at high temperatures. Thus, high temperature resistance and super hydrophobic functions are achieved.

[0022] (2) The present invention provides a method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating, wherein carbon fiber, silicone resin containing inorganic filler, and a binder are dispersed in water, deposited on a substrate by air spraying or brushing, and cured and heat treated to obtain a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating. The preparation method of the present invention has simple process, low cost, and can be constructed over a large area. DETAILED DESCRIPTION

[0023] The following is a detailed description of a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating provided by the present invention and its preparation method and application in combination with the embodiments, but they should not be understood as limiting the scope of protection of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0024] Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all methods known to those skilled in the art.

[0025] Example 1

[0026] A method for preparing a high temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating, the specific steps are:

[0027] Step 1: Prepare a carbon fiber / silicone resin dispersion, mix 1g of carbon fiber with a diameter of 7μm and a length of 500μm, 4g of silicone resin containing 1wt% titanium dioxide (TiO2), 4g of silicone resin emulsion and 40g of water, and perform ultrasonic dispersion in an ultrasonic cell crusher with an ultrasonic power of 600W and a time of 5min;

[0028] Step 2: Prepare the carbon fiber / silicone resin composite coating, spray the carbon fiber / silicone resin dispersion onto the aluminum alloy substrate by air, and cure it in an oven at a curing temperature of 200°C for 5 hours;

[0029] The third step: heat-treat the prepared carbon fiber / silicone resin composite coating by using a flame spray gun with a flame temperature of 1000°C and a time of 30s to obtain a high-temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating with a water contact angle of 170° and a rolling angle of 1°. It still maintains super-hydrophobicity after 5 hours at 450°C.

[0030] Example 2

[0031] A method for preparing a high temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating, the specific steps are:

[0032] Step 1: Prepare a carbon fiber / silicone resin dispersion, mix 1g of carbon fiber with a diameter of 10μm and a length of 1mm, 6g of silicone resin containing 5wt% titanium dioxide (TiO2), 6g of epoxy resin emulsion and 40g of water, and perform ultrasonic dispersion in an ultrasonic cell crusher with an ultrasonic power of 400W and a time of 10min;

[0033] Step 2: Prepare the carbon fiber / silicone resin composite coating, apply the carbon fiber / silicone resin dispersion onto the glass substrate, and cure it in an oven at a curing temperature of 200°C for 1 hour;

[0034] The third step: heat-treat the prepared carbon fiber / silicone resin composite coating. Use a muffle furnace to perform high-temperature treatment on the coating at a temperature of 800°C for 20 minutes to obtain a high-temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating. The water contact angle of the coating is 165°, the rolling angle is 3°, and it still maintains super-hydrophobicity after 24 hours at 400°C.

[0035] Example 3

[0036] A method for preparing a high temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating, the specific steps are:

[0037] Step 1: Prepare a carbon fiber / silicone resin dispersion, mix 4 g of carbon fiber with a diameter of 50 nm and a length of 300 nm, 2 g of silicone resin containing 0.1 wt% silicon dioxide (SiO2), 2 g of aluminum dihydrogen phosphate and 20 g of water, and perform ultrasonic dispersion in an ultrasonic cell crusher at an ultrasonic power of 300 W for 20 min;

[0038] Step 2: Prepare the carbon fiber / silicone resin composite coating, spray the carbon fiber / silicone resin dispersion onto the alumina ceramic substrate by air, and cure it in an oven at a curing temperature of 100°C for 5 hours;

[0039] The third step: heat-treat the prepared carbon fiber / silicone resin composite coating. Use a muffle furnace to treat the coating at high temperature at 600°C for 40 minutes to obtain a high-temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating. The water contact angle of the coating is 167°, the rolling angle is 3°, and it still maintains super-hydrophobicity after 20 hours at 400°C.

[0040] Example 4

[0041] A method for preparing a high temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating, the specific steps are:

[0042] Step 1: Prepare a carbon fiber / silicone resin dispersion, mix 2g of carbon fiber with a diameter of 6μm and a length of 500μm, 2g of silicone resin containing 5wt% graphene, 2g of polyurethane emulsion and 30g of water, and perform ultrasonic dispersion in an ultrasonic cell crusher with an ultrasonic power of 500W and a time of 10min;

[0043] Step 2: Prepare the carbon fiber / silicone resin composite coating, brush the carbon fiber / silicone resin dispersion onto the alumina ceramic substrate, and cure it in an oven at a curing temperature of 150°C for 3 hours;

[0044] The third step: heat-treat the prepared carbon fiber / silicone resin composite coating. Use a muffle furnace to treat the coating at high temperature at a temperature of 500°C for 20 minutes to obtain a high-temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating. The water contact angle of the coating is 160° and the rolling angle is 4°. It still maintains super-hydrophobicity after 20 hours at 400°C.

[0045] Example 5

[0046] A method for preparing a high temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating, the specific steps are:

[0047] Step 1: Prepare a carbon fiber / silicone resin dispersion, mix 1g of carbon fiber with a diameter of 7μm and a length of 600μm, 4g of silicone resin containing 1wt% aluminum hydroxide (Al(OH)3), 4g of acrylic emulsion and 40g of water, and perform ultrasonic dispersion in an ultrasonic cleaning machine with an ultrasonic power of 500W and a time of 20min;

[0048] Step 2: Prepare the carbon fiber / silicone resin composite coating, apply the carbon fiber / silicone resin dispersion onto the aluminum alloy substrate, and cure it in an oven at a curing temperature of 200°C for 5 hours;

[0049] The third step: heat-treat the prepared carbon fiber / silicone resin composite coating by using a flame spray gun with a flame temperature of 800°C and a time of 2 minutes to obtain a high-temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating with a water contact angle of 168° and a rolling angle of 2°. It still maintains super-hydrophobicity after 10 hours at 400°C.

Claims

1. A method for preparing a high temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating, characterized in that: The method steps include: Carbon fiber, silicone resin containing inorganic filler, and a binder are mixed in water, and a carbon fiber / silicone resin dispersion is obtained after ultrasonic dispersion; the dispersion is deposited on a substrate by air spraying or brushing, and a carbon fiber / silicone resin composite coating is obtained after solidification; and the carbon fiber / silicone resin composite coating is heat-treated to obtain a carbon fiber / silicone resin composite super-hydrophobic coating containing a nanostructure.

2. The method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating according to claim 1, characterized in that: The diameter of carbon fiber is 1nm~20μm, and the length is 10nm~10mm.

3. The method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating according to claim 1, characterized in that: The inorganic filler includes one or more of metals, oxides, nitrides, carbides, sulfides, silicides, halides, hydroxides and carbon materials.

4. The method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating according to claim 3, characterized in that: The inorganic filler accounts for 0.1 to 50% of the silicone resin by mass.

5. The method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating according to claim 1, characterized in that: The mass percentage of the silicone resin to the carbon fiber is 0.1-500%.

6. The method for preparing a high temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating according to claim 1, characterized in that: The binder is a water-based binder, including one or more of silicone resin emulsion, polyurethane emulsion, epoxy resin emulsion, polyimide emulsion, vinyl acetate emulsion, acrylic emulsion, polyvinyl acetate emulsion, polyvinyl alcohol, aluminum dihydrogen phosphate, potassium silicate and silica sol.

7. The method for preparing a high temperature resistant super-hydrophobic carbon fiber / silicone resin composite coating according to claim 6, characterized in that: The usage amount of the binder is 0.5 to 500% of the mass fraction of the carbon fiber.

8. The method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating according to claim 1, characterized in that: The ultrasonic dispersion refers to ultrasonic dispersion using an ultrasonic cleaning machine or an ultrasonic cell crusher, with a power of 20 to 1000 W and a time of 1 to 30 minutes.

9. The method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating according to claim 1, characterized in that: The matrix includes metal, ceramic, organic matter, carbon material and composite material.

10. The method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating according to claim 1, characterized in that: The curing process is carried out in an oven, the curing temperature is from room temperature to 300° C., and the curing time is 30 minutes to 5 hours.

11. The method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating according to claim 1, characterized in that: The heat treatment refers to high temperature treatment in a muffle furnace or flame treatment using a flame spray gun, the temperature is preferably 500 to 2000° C., and the time is preferably 20 seconds to 2 hours.

12. The method for preparing a high temperature resistant super hydrophobic carbon fiber / silicone resin composite coating according to claim 1, characterized in that: The nanostructure refers to hydrophobic nano-scale oligomers (the size of the oligomer is 10-200 nm) generated by depolymerization of silicone resin at high temperature.