Preparation And Properties Of Silica-Based Superhydrophobic Coating On Glass?Aluminum Alloy

Superhydrophobic materials have been paid more and more attention because of their special practical application functions,such as non-metallic glass surface antireflection,self-cleaning,metal surface anti-corrosion,anti icing and so on.On the basis of superhydrophobic theory,superhydrophobic functional coatings were fabricated on two different properties(non-metal/metal)substrates,and silicon dioxide was used as modified raw material to prepare durable wear-resistant superhydrophobic coatings on typical non-metal glass and typical metal aluminum alloy substrates,and their specific practical application properties were studied respectively to expand the silica based silane Application range of superhydrophobic coating.The main contents of this paper are as follows:1.By traditional sol-gel method,tetraethyl silicate(TEOS)was hydrolyzed in alkaline environment to obtain SiO₂ sol-gel,and trimethylethoxysilane(TMES)and perfluorosilane(FAS-17)were bonded on the surface of SiO₂ by hydrothermal reaction to prepare superhydrophobic coating on the surface of glass.2.To explore the influence of the amount of ammonia,TEOS and TMES on the wettability of the coating,the micro nano roughness texture formed by the different dipping speed of 1000-1400?m/s makes the surface have a certain roughness,reduces the solid-liquid contact fraction,the self-cleaning effect of the coating is obvious,and the light transmittance of the coating is 91.54%-96.36%in the range of visible light.After immersion in deionized water for 72 hours,the static water contact angle of the coating surface decreased from154±1.4°to 150.3±4.5°.After exposure to air for 30 days,the contact angle of the surface changed from 154±1.4°to 151±3.7°and it was still superhydrophobic.3.The hydrolysis products of TEOS,TMES and perfluorosilane(FAS-17)were dried and ground into spherical SiO₂ nanoparticles in alkaline condition.The fluorinated SiO₂nanoparticles have excellent hydrophobic effect,which makes corrosion more difficult.In this study,first of all,laser textured aluminum alloy substrate,pre-set rough bottom layer,using electrodeposition method in laser etching textured aluminum alloy surface deposition of silica nanoparticles,the coating has corrosion resistance and wear resistance.The"honeycomb"structure formed by texturing can effectively store the modified fluorinated SiO₂nano-particles,and the dispersion of the particles can be deposited on any metal substrate by this method.4.To explore the change of wettability of superhydrophobic surface under different texture density,deposition voltage and deposition time,and select the best experimental conditions.The optimum conditions for the preparation of superhydrophobic coating are 75%texture density,10V deposition voltage and 5min deposition time.The coating has high hydrophobicity,and the water contact angle is about 158.2±4.8°.When exposed to air for 8months and immersed in deionized water for 7 days,the superhydrophobic property can be maintained.Under the pressure of 10k Pa,after 600cm of abrasive paper wear distance,it still keeps its non-wetting performance,showing excellent wear resistance.The electrochemical results show that the capacitance arc diameter of the substrate is much higher than that of other substrates.At the same time,the electrochemical impedance Z value increased by three orders of magnitude.When the super hydrophobic coating is sprayed with water spray at–15?,there is only a water bead ice layer on the edge of the prepared surface,and the contact area is only 3%,which reduces the energy transfer from the water drop to the surface of the super hydrophobic coating,makes it difficult for the water drop to freeze and has good anti icing behavior.