海泡石的酸活化及亲水性表面修饰

Acid Activation Treatment of Sepiolite and Its Hydrophilic Surface Modification

采用酸活化法对海泡石进行提纯改性得到酸活化海泡石,依次用苯基三乙氧基硅烷和浓硫酸对酸活化海泡石进行硅烷偶联剂处理和磺化改性,制备有机海泡石。考察了酸活化所用盐酸浓度和处理时间对海泡石改性效果的影响,通过FTIR、XRD、BET等测试手段分别对酸活化海泡石和有机海泡石进行结构和形貌表征。结果表明:酸活化处理使海泡石中部分Mg^(2+)被H^+取代,同时失去边缘与Mg^(2+)配位的结构水,骨架Si-OH增加,比表面积和微孔孔容体积增大。提高盐酸浓度和延长反应时间可促进海泡石的酸活化效果;海泡石经亲水性表面修饰后可改善与有机介质之间的相容性。

Sepiolite was purified by acid activation method, and then with hydrophilic surface modification by phenyltriethoxysilane and sulfuric acid to prepare organic sepiolite. The effects of hydrochloric acid concentration and treatment time on the modification effect of sepiolite were investigated. The structure and morphology of acid activated sepiolite and organic sepiolite were characterized by FTIR, XRD and BET. The results showed that part of Mg2- was replaced by H＋, and the structural water which coordinated with the end position Mg2＋ was moved, thus resulting in the increase of Si-OH as well as the specific surface area and the pore volume of the micropores. Increasing the concentration of hydrochloric acid and prolonging the reaction time can enhance the effect of acid activation on sepiolite. Meanwhile, after hydrophilic surface modification, organic sepiolite can improve its compatibility with polar medium.