改性多孔氧化硅材料的差热性能分析

Differential Thermal Analysis of Modified Porous Silica

采用溶胶凝胶+超临界干燥法制备了纳米氧化硅气凝胶块体,用KH550和氟硅烷对其进行了表面改性,利用DTA分析了两种改性剂对多孔氧化硅的接枝特性。结果表明,KH550与氟硅烷相比,可与气凝胶表面接枝反应良好,降低表面羟基含量以及对空气中水分的吸附,从而在超临界干燥之后形成结构强度最高的块体。

Porous silica prepared by the sol gel surpercritical fluid drying processing was modified by KH550 and fluoro-alkyl silanes,and tested by DTA. The results showed,fluoro-alkyl silanes can be grafted on surface of prepared porous silica effectively which could reduce hydroxyl content of silica surface and prevent silica from the formation of absorbent water to obtain maximum bulk strength.