PREPARATION OF WATER-REPELLENT COATING FILMS BY THE SOL-GEL METHOD

摘要

Water-repellent SiO_2 coating films on glass substrates were prepared from the heptadecafluorodecyl-trimethoxysilane (FMS) and the porous SiO_2 films; the porous films were prepared by the sol-gel method starting from Si(OC_2H_5)_4 containing polyethyleneglycol. The coating films obtained with heating at 460°C showed high contact angles larger than 100°C for water.The content of water in sols was found to affect the contact angles of the coating films obtained. The contact angles were also closely related to the amount of SiOH groups and the porosity of the porous SiO_2 films. The high contact angles of the coating films are concluded to result from the reaction of SiOH with FMS embedded in the pores of the films.