Abstract:Several fluoride-containing silane coupling agents with short fluorocarbon chains were synthesized via the anionic ring-opening polymerization and hydrosilylation reaction using trifluoropropylmethylcyclotrisiloxane(D3F), dimethylchlorosilane, methyldichlorosilane and vinyltrimethoxysilane(VTMS) as reactants. The substrate on the glass plate was prepared by spin-coating of nano-silica sol, and the hydrophobic coating was obtained after the modification of silane coupling agents. The effects of silane coupling agents on the hydrophobicity, adhesion, hardness and transmittance of the coatings were investigated. The results showed that for the same type fluoride-containing silane coupling agents, the contact angle increased with the fluorine content in the agents. For the fluoride-containing silane coupling agents which had the similar molecular weight and fluorine content, the coating modified by the linear type coupling agent was more hydrophobic than the one modified by the branched type. Among the fluoride-containing silane coupling agents in this work, the coating modified by the branched type with a degree of polymerization of 9(DF3) showed the biggest contact angle, about 141.6°. The adhesion level of the hydrophobic coatings in all cases reached to level 1 and the hardness reached to H, while the visible light transmittance was higher than 82.9%. The hydrophobic coatings also had good self-cleaning property.