硅烷偶联剂KH550对超细石英粉的改性

Surface Modification of Ultrafine Silica Powder with Silane Coupling Agent KH550

采用γ-氨丙基三乙氧基硅烷(KH550)对超细石英粉进行表面改性。探索最佳的改性条件,并对改性后的超细石英粉进行傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)和Zeta电位的表征,分析计算了改性前后超细石英的粒度分布和表面羟基数变化。结果表明,KH550添加量为1.6%、反应时间为8h、反应温度为120℃时,对超细石英粉改性效果最佳;超细石英粉在改性前后表面羟基数由原来的1.74个/nm2减少到0.42个/nm2,疏水性提高;改性后超细石英Zeta电位绝对值较改性前提高,通过粒度分析,改性后超细石英粉细粒级含量增多,颗粒分散性提高;FTIR和XPS表明KH550在超细石英粉表面附着良好,为化学吸附,改性效果明显。

The surface of ultrafine silica powder was modified with γ-aminopropyltriethoxysilane（KH550）.The modification mechanism was investigated by FTIR,XPS and Zeta potential.The particle size distribution and surface hydroxyl number of the ultrafine silica powder before and after modified with KH550 were analyzed and calculated.The results show that the best modification conditions obtained were as follows：KH550 content was 1.6%,reaction temperature was 120 ℃ and reaction time was 8 h.The surface hydroxyl number of the ultrafine silica powder was 1.74 nm^2 before modification,but after modified with KH550,the hydrophobicity increased and the surface hydroxyl number was reduced to 0.42 nm^2.The absolute value of Zeta potential has increased after modification.The particle size analysis showed that the fine grade content increased after modified with KH550,and particle dispersion was improved obviously.From FTIR and XPS spectra analysis can be seen that KH550 attached to the surface of ultrafine silica powder well as chemical adsorption.