Preparation Of Super-amphiphobic Coating By Combining Fluoroalkyl Silane With Nano SiO₂

In this paper, a super-amphiphobic surfaces were prepared by combining sol-gel method with free radical polymerization method. Fluorine monomer and γ-Methacryloxypropyl trimethoxy silane（γ-MPS） were monomer, tetrahydrofuran（THF） was solvent, fluoroalkyl silane copolymer（PFAS） was prepared by free radical polymerization. Then, a certain amount of tetraethoxysilane（TEOS）, Deionized water and SiO₂ nanoparticles were added to dispersed in PFAS solution to obtain a homogeneous hybrid sol. The hybrid sol was coated on glass surface by dip-coating method. After drying, super-amphiphobic surfaces were obtained. The property and structure of coating were tested and chracteristiced. The research content and results of this paper included the following several aspects:（1） Fluorine monomer and γ-Methacryloxypropyl trimethoxy silane（γ-MPS） were monomer, PFAS was prepared by free radical polymerization. Hexafluorobutylmethacrylate（HFMA） and Dodecafluoroheptyl- methacrylate（DFMA） were fluorine monomer. Hydrophobic properties and mechanical properties of PFAS were discussed. The results showed that. The contact angle of water, glycerol and ethylene glycol of PFAS could reach 113 °, 104 ° and 99 ° when the molar ratio of DFMA and KH-570 was 1: 1.. Adhesion and hardness were 2 and 2B, respectively. The contact angle of water, glycerol and ethylene glycol of PFAS could reach 108 °, 102 ° and 97° when the molar ratio of HFMA and KH-570 was 2: 1. Adhesion and hardness were also 2 and 2B, respectively. In summary, the PFAS which was prepared by DFMA and γ-MPS had a better hydrophobicity and oleophobicity.（2） The PFAS had a good hydrophobicity and oleophobicity, but the adhesion and hardness were very poor. So TEOS was used to improve adhesion and hardness. A homogeneous hybrid sol could be prepared by the hydrolysis of TEOS. The silanol groups of hybrid sol could condensated with PFAS. Hybrid sol also could graft on glass surface, so it could improve the adhesion. TEOS were added in PFAS solution to obtain PFAS hybrid sol. The PFAS hybrid sol was coated on glass surfaces. After drying, PFAS hybrid coating was obtained. Hydrophobic properties and mechanical properties of PFAS hybrid coating were also discussed. Properties of PFAS hybrid coating were tested and charactcterized by Contact angle measurements, Fourier transform infrared spectroscopy（FTIR）, Scanning electron microscopy（SEM）, Ultraviolet-visible spectrometer（UV-Vis） and Thermal gravimetric analysis（TG）. The results showed that the hydrophobicity and oleophobicity of coating had a little decrease when TEOS was added, but the adhesion and hardness had a great improved. PFAS hybrid coating had a good hydrophobicity, oleophobicity and mechanical property when the molar ratio of PFAS and TEOS was 1: 2. The contact angle of water, glycerol and ethylene glycol, were 102 °, 95 ° and 92 °, and the adhesion and hardness were 0 grade and H. The transmittance was more than 90%. The PFAS hybrid coating had a good thermal stability under 270℃.（3） The SiO₂/PFAS hybrid coating was prepared by PFAS hybrid sol and SiO₂ particles. The optimum conditions of preparing the SiO₂/PFAS hybrid coating were investigated. SiO₂/PFAS hybrid coating was charactcterized by Scanning electron microscopy（SEM）, Atomic force microscope（AFM） and Thermal gravimetric analysis（TG）. Contact angle measurements, hardness, adhesion and transmittance were also tested. It was found that SiO₂/PFAS hybrid coating which was prepared by（80²40）nm SiO₂ had a good hydrophobic, oleophobic and mechanical performance. The contact of water, glycerol and ethylene glycol could reach 154 °, 151 ° and 150 ° when the mass ratio of SiO₂ and PFAS was 0.3. The transmittance was more than 85%. The SiO₂/PFAS hybrid coating has a uniform micro-nano roughness surface. The average roughness（Ra） was 352 nm and the micro roughness（Rms） was 458 nm. The SiO₂/PFAS hybrid coating had a good thermal stability under 280℃.