【摘要】 以酚醛树脂为碳源、正硅酸乙酯为硅源,辅以硝酸镍结构助剂合成了系列硅碳二元干凝胶。采用FT- IR、小角X射线散射(SAXS)和SEM等技术研究镍离子在硅碳二元凝胶形成过程中的作用以及对凝胶结构和形貌的影响。结果表明,不含镍盐的硅碳二元凝胶主要由直径为30 nm的球形颗粒组成;而添加镍盐的凝胶由于颗粒间的团聚与自组装,形成了直径100 nm形状不规则的次级颗粒。由于次级颗粒表面粗糙度增加,使其具有较大的表面分形维数。此外,酚醛树脂中的羟基和硅胶颗粒表面的羟基在凝胶形成过程中会发生化学交联,限制了硅胶初级颗粒长大。更多还原

【Abstract】 A series of binary carbonaceous silica xerogels with nickel nitrate as additive were prepared by using phenolic resin and TEOS. The influences of nickel nitrate on the structure and morphology of the binary carbonaceous silica xerogels were studied by FT-IR, SAXS and SEM techniques. The re-sults indicated that the binary carbonaceous silica xerogels without nickel nitrate were composed of spherical particles (secondary particles) with several tens nanometers in diameter. After employment of nickel nitrate, the diameter of the nanoparticles constituting the xerogels increased up to about 100 nm because of the aggregation of the secondary particles. Simultaneously, the nanoparticles had a high surface fractal dimension due to their rough surface. In addition, phenolic resin reacted with sili-ca colloidal particles, and thus limited the growth of the elementary silica particles.更多还原