TiO2/尿素核壳纳米颗粒的制备及其电流变性能∗

摘要

Core-shell-structured TiO2/Urea nanoparticles were synthesized with tetrabutyl titanate and urea by using a hydrolysis method.The microstructure of the particles were observed by scanning electron microscope (SEM)and transmission electron microscopy (TEM),which indicated that the particles are monodispersed sphere (400-500 nm)with complete core-shell structure.FT-IR results further proved that the surface of the TiO2 particles is coated with urea.X-ray diffrantion (XRD)results indicated that the particles present amor-phous structure.Both TiO2/urea particles and TiO2 particles were used to prepare electrorheological (ER)flu-ids with the same particles volume fraction.Their ER properties were tested and compared.The results indica-ted that the TiO2/urea particles-based ER fluid presents much higher yield stress than the pure TiO2 particles-based material.Besides,the shear stress of the TiO2/urea particles-based ER fluid keeps stable within a wide range of shear rate.%在醇盐水解法制备TiO2颗粒的过程中加入尿素,制备TiO2/尿素核壳颗粒。采用 SEM和 TEM对颗粒的形貌进行表征,结果表明 TiO2/尿素颗粒呈规则球形,粒径为400~500 nm,具有良好的单分散性和完整的核壳结构；FT-IR分析表明,尿素成功包覆在TiO2颗粒表面；XRD 分析表明,TiO2/尿素核壳颗粒呈无定形态。分别以 TiO2/尿素核壳颗粒和纯 TiO2颗粒为分散相制备同浓度的电流变液,性能测试结果表明,TiO2/尿素电流变液比纯 TiO2电流变液具有更高的剪切屈服强度,且剪切应力在较宽的剪切速率范围内(＜1000 s－1)保持稳定。