中文摘要：

利用分散聚合法制备单分散的Ps及交联Ps微球，干燥后经CTAB重新分散制得PS微球分散液；无定型Ti02溶解于H202制得钛前驱体过氧钛酸（PTC），并将PTC缓慢滴加入PS微球分散液中，强烈搅拌加热制备得到了Ti02／IS复合微球。经扫描电镜观测，发现微球由于在过氧介质中反应表面发生了破裂；采用化学稳定性更好的交联Ps微球，制得表面形貌完整的复合微球。经x射线衍射测定，证明复合微球中Ti02为锐钛矿型。因金红石Ti02介电常数强于锐钛矿型，其电流变性能较强。为了制备金红石Ti02／PS复合微球，向体系加酸以调节体系酸度，发现当加入0．5ml浓硫酸时，制备得到了表面形貌完整，且表面Ti02晶型为金红石的复合微球，并且再加入少量PVP后，微球表面Ti02的量明显增多，经热重分析测定其含量为8％。将复合微球分散在氨基硅油中，测试其在不同电压下粘度与剪切应力随剪切速率的变化。结果表明使用复合微球作为电流变液固体相时沉降稳定性比纯提Ti02高了25倍；当分散体系两端电压为3000V时，其屈服压力为525Pa，最大粘度278．9Pa·s。

英文摘要：

Monodisperse PS and cross-linked PS microspheres were prepared by dispersion polymerization; the samples were dried and re-dispersed by CTAB. Peroxo titanic acid （PTC） was prepared by dissolving amorphous TiO2 into H202. Then PTC was dropped into dispersion of PS, and TiO2/PS composite mierospheres were prepared after heating and tempestuously stirring. The microspheres of PS were broken for reacting in peroxide medium by scanning electron microscopy （SEM）. In order to get unbroken composite micro- spheres, the cross-linked PS microspheres that had more chemical stable were used. The TiO2 in composite mierospheres was anatase by X-ray diffraction（XRD）. For the dielectric constant of rutile TiO2 was bigger than that of anatase, it had more strong performance of the electrorheological（ER） effect. The acid was added to adjust the acidity of the system for preparing the rutile TiO2/PS composite microspheres. Then it was found that the rutile TiOJPS composite microspheres were prepared when concentrated sulfuric acid was added. And the morphology of composite mierospheres was complete when 0.5 ml concentrated sulfuric acid was added. And then the quantity of the TiO2 on surface increased significantly when a small amount of PVP was added. The content of TiO2 was 8% by thermal gravimetry （TG）. Finally the prepared composite microspheres were dispersed into amino silicone, voltage viscosity and shear stress with shear rate were tested. The results showed that the sedimentation stability of the electrorheological fluid which used composite mi- crospheres as solid phase was 25 times higher than the pure PS microspheres. And when the voltage of dispersion system was 3000 V, the yield pressure of dispersion could reach 525 Pa and the maximum viscosity of dispersion was 278.9 Pa.s.