超声辅助沉淀法制备疏水性纳米SiO_2

Preparation of Hydrophobic Nano-SiO_2 by Ultrasound-assisted Precipitation Method

采用超声沉淀法制备出SiO2纳米粉体,利用硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)对其进行了表面改性,并利用红外光谱(FT-IR)、热重(TG)、接触角、透射电镜(TEM)等方法对SiO2的结构和性能进行了表征,并研究了KH-570用量和改性时间对SiO2活化指数的影响。结果表明:与普通搅拌相比,超声更利于纳米SiO2的制备和改性。超声条件下,KH-570成功接枝到SiO2纳米粒子的表面。且改性后的SiO2疏水性提高,在无水乙醇中的分散状态得到明显改善。当改性剂用量为6 mL,改性时间为1 h时,SiO2纳米粒子的活化指数达到100%。

In this paper,nano-silica particles were prepared by ultrasound-assisted precipitation method,and were modified by silane coupling agent KH-570.The structure and properties of silica were characterized by FTIR,TG,contact angel and TEM.The effects of content of KH-570 and modification time on activation index of silica were studied.The result showed that compared with normal stirring,ultrasound was more conducive to preparation and modification of silica.Under the ultrasound condition,KH-570 was successfully grafted to the surface of silica nano-particles.After modification,silica were rendered better hydrophobic and the dispersion significantly improved.The activation index of silica reached 100% when the content of KH-570 was 3 mL and the modification time was 1 h.