稀土铈改性二氧化钛微粉的制备及其介电性质

Preparation and Dielectric Characteristics of Fine Powder of Modified Titania Doped by Ce

用Sol gel法制备了掺杂稀土元素铈的二氧化钛微粉 ,测试了它的介电常数和电导率。由该材料作分散相与甲基硅油配制了无水电流变液 ,对其电流变性能进行了研究。实验结果表明 ,随稀土含量增加二氧化钛颗粒的介电常数和电导率增加 ,材料的电流变性能也发生很大的改变。存在一个稀土含量的最佳浓度范围 ,在此区域介电常数取得最大值 ,电流变液的剪切强度也取得极大值 ,比纯二氧化钛电流变液的流变性能提高 5倍以上。

A kind of fine powder of modified titania (TiO 2) doped by Ce is synthesized by the means of Sol gel technique. The thermal character of Gel and crystal structure of particles is also given with DSC, TG and XRD. Dielectric properties of the powder and shear stress of ER fluids made of modified titania and methyl silicone are measured. The results show that the modified titania particles have bigger dielectric constants and conductivity than that of the pure ones. At the same time, the modified titania based ER fluids show more stronger ER activation than that of the pure titania based ER fluids. A suitable range of RE/Ti mole ratio, in which both the dielectric properties of particles and shear stress of ER fluids get their maximums, can be observed. And this shear stress is 5 times stronger than that of pure titania ER fluids.