氢化锆表面KH570/A171改性硅溶胶膜层结构及性能

Structure and Performance of KH570/A171 Modified Silica Sol Film on Zirconium Hydride Surface

以硅酸乙酯(TEOS)、γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(硅烷偶联剂KH570)和乙烯基三甲氧基硅烷(硅烷偶联剂A171)等为主要原料制备硅烷偶联剂KH570/A171改性硅溶胶,进而采用浸渍提拉法在氢化锆表面制备溶胶膜层。红外光谱(FTIR)分析显示,硅烷偶联剂能有效参与溶胶共聚反应。透射电镜(TEM)分析表明,硅烷偶联剂的逐一加入有利于胶粒粒径细化,提高和维持胶粒之间亲和能力。扫描电镜(SEM)分析显示,使用硅烷偶联剂KH570和A171改性的有机硅溶胶,可在氢化锆表面制备干燥后无裂纹溶胶膜层,烧结溶胶膜层存在微裂纹而无明显崩落;溶胶膜层表面元素分布均匀,烧结后存在碳残余。真空热放氢实验表明,在氢化锆表面制备的烧结硅溶胶膜层,起到了阻氢渗透的作用。600℃二氧化碳气氛中,烧结硅溶胶膜层具备阻碍氧渗透能力,对氢化锆基体有抗高温氧化作用。

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 a dip-coating method. FTIR analysis shows that the coupling agent could participate in the copolymerization reaction of the sol effectively. TEM analysis indicates that it is advantageous to refine colloidal particle size, improve and maintain the affinity between them as KH570 and A171 are added one by one into the sol. SEM analysis reveals 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 demonstrates that the preparation of sintered sol film on zirconium hydride could resist hydrogen permeation. In CO2 atmosphere at 600 ℃, oxygen diffusion could be also hindered by the sintered silica sol film, which shows oxidation resistance for zirconium hydride substrate.