COATING AND WATER PERMEATION PROPERTIES OF SIO2 THIN-FILMS PREPARED BY THE SOL-GEL METHOD ON NYLON-6 SUBSTRATES

Nylon-6 substrates were coated with SiO2 thin films by the sol-gel met hod and their water permeability coefficient was evaluated. Methyltrie thoxysilane (MTES) and tetraethoxysilane (TEOS) were used as starting materials. The addition of MTES to TEOS has enabled the formation of-c rack-free thin films on the substrates. The thin films strongly adhere d to the substrates. The water permeability coefficients of nylon-6 su bstrates coated with these thin films decreased with the increase in t he ratio of TEOS to the total alkoxides. The pretreatment of the nylon -6 substrates with gamma-aminopropyltriethoxysilane was found to be ef fective to suppress the water permeability. The water permeability was suppressed by about 40% under the optimal condition.