Preparation and properties of methyl-situ-modified sol-gel hydrophobic anti-reflective SiO_2 coating
Methyl-situ-modified silica sols were obtained by hydrolysis and co-condensation reactions occurred in base-catalyzed system by carefully controlling the sol-gel process of Methyltriethoxysilane(MTES) and Tetraethoxysilane(TEOS).Hydrophobic-antireflective silica film was then prepared by dipping-coating technique from the modified sols.As a result,the hydrophobicity of antireflective coating was highly improved.The properties of the films were characterized with atomic force microscope(AFM),ultraviolet-visible spectrum(UV-Vis) and contact angle analyzer measurement.An Nd:YAG laser(1 064 nm,1 ns) was used to irradiate the film by "R on 1" method and the damage thresholds were measured.In addition,comparison was carried out between organically modified coating and pure silica coating.The results showed that the hydrophobicity and laser damage resistance of the coating were greatly improved by proper modification and high transmission was maintained.