摘要
利用 W/O微乳液法,分别由水/Span80或 DBS/正戊醇/环己烷形成 W/O 微乳液,将钛酸盐在微乳中以水核为中心水解,制得包覆表面活性剂的TiO2粒子.包覆表面活性剂可显著提高TiO2的电流变活性,且非离子型表面活性剂的效果远好于离子型表面活性剂.一种典型的颗粒/硅油体积比为 31%的电流变液在 3kV/mm直流电场下的剪切应力为 1.4kPa,约为纯 TiO2的 3倍,漏电流密度小于 25μA/cm2.当 Span80与 TiO2的质量比为 7%~13%时有最佳电流变效应.包覆适量的非离子表面活性剂可明显优化电流变液的温度效应,改善颗粒的悬浮稳定性.
In the micro--emulsion system of H2O/Span or DBS/n--amyl alcohol/xylene, the particles of TiO2 coated by surfactant are obtained. The Electrorheological (ER) behavior of the suspension made of TiO2 coated by surfactant in dimethylsilicone oil with a 31% volume fraction is investigated. The result showed that covering surfactant could increase the ER activity of TiO2. In the electrical field of 3kV/mm, the shear stress is about 1.4kPa, while the current density is only 25μA/cm2. This method has a better effect than that of adding surfactant in silicone oil simply. The content of coated surfactant had a strong influence on ER behavior. At the same time, because R = [H2O]/[Surfactant] could control particles' granularity and content of coated surfactant in the method of W/O micro--emulsion technique, the sedimentation could be controlled and modified by surfactant.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2001年第3期308-312,共5页
Chinese Journal of Materials Research
基金
国家自然科学基金重点资助项目59832090
航空基金资助项目98G53107.