Structure and performance of KH570/A171 modified silica sol film on zirconium hydride surface

Abstract:

Silane coupling agent modified silica sol was prepared with ethyl silicate (TEOS), 3-Methacryloxypropyltrimethoxysilane (silane coupling agent KH570) and vinyl trimethoxy silane (silane coupling agent A171) as main raw material, and then modified silica sol film on zirconium hydride was made by dip-coating method. FTIR analysis showed that coupling agent could participate in copolymerization reaction of the sol effectively. TEM analysis showed that it’s advantageous to refine colloidal particle size, improve and maintain the affinity between them as KH570 and A171 were added one by one into the sol. SEM analysis showed that dried crack-free sol film could be prepared on zirconium hydride substrate using KH570 and A171 modified silica sol. Micro cracks exist on the sintered sol film but without apparent flaking. Elements distribute evenly on the surface of the sol film in which residual carbon exists after sintering. Thermal hydrogen release experiment in vacuum demonstrated the preparation of sintered sol film on zirconium hydride could resistant hydrogen permeation. In CO₂ atmosphere under 600℃, oxygen diffusion could also be hindered by the sintered silica sol film, which shows oxidation resistance for zirconium hydride substrate.