在醇/水体系中,采用溶胶/凝胶法制备了硅烷偶联剂改性的纳米二氧化硅包覆的铝颜料,并采用SEM、FTIR等分析方法对包覆效果进行表征,检测了包覆产物的耐碱性,并对过程机理进行了分析.结果表明,硅烷偶联剂改性的二氧化硅可以在铝颜料表面形成一层包覆层,且硅烷偶联剂的含量越高,包覆层中颗粒物的含量越少,而有机膜的含量越高.硅烷偶联剂改性二氧化硅包覆铝颜料在pH值为11的碱性水溶液中,经720 h后,析出的氢气量为未包覆产品的2.7%,表明用此方法制备的铝颜料具有良好的耐碱性.硅烷偶联剂和二氧化硅并不是简单的混合,而是彼此缩合形成了均一的杂化材料.

Aluminum pigments encapsulated by nano-silicon dioxide modified by silane coupling agent were prepared with sol/gel method in the ethanol/water media and characterized with SEM and FTIR.Their stability in alkaline aqueous media was also examined.In addition,the mechanism of the course was analyzed.The silicon dioxide modified by silane coupling agent can form a covering layer on the surface of the aluminum pigments.The higher the content of the silane coupling agent,the less the granules in the covering layer and the higher the content of the organic film.The volume of the hydrogen evolved by the aluminum pigments encapsulated by nano-silicon dioxide modified by silane coupling agent was 2.7 percent of that evolved by unencapsulated ones in the alkaline aqueous media of pH=11 after 720 h.The silane coupling agent and silicon dioxide were not mixed simply but were polymerized,resulting in the formation of a homogeneous material.