摘要
采用sol gel法制备了掺杂稀土改性TiO2 颗粒 ,与甲基硅油配制成电流变液 ,对电流变液的介电性能进行了测试 ,结果表明改性后TiO2 电流变液的介电常数和介电损耗比纯TiO2电流变液均显著提高 ,其中介电常数提高 2～ 3倍 ,Δε′ =ε′10 0Hz～ε′10kHz明显增大 ,1kHz的介电损耗角正切大于 0 .1。稀土含量对材料的介电性能有重要影响 ,RE/Ti摩尔比为 0 .1左右电流变液的介电常数与介电损耗达到最大值。稀土掺杂引起TiO2电流变液的介电性能改变是导致改性TiO2 电流变液流变学行为变化的起因。另外 。
The dielectric properties of ER fluids made of rare earth (RE) doped titania(TiO 2), synthesized by the means of sol gel technique, are investigated. In the results, the perrimitivity of RE doped TiO 2 ER fluids are 2～3 times bigger than that of pureTiO 2 ER fluids, loss tangent is bigger than 0.1 at 1kHz, and a strong decrease of the perrimitivity Δ ε′=ε ′ 100Hz ～ ε ′ 1kHz in RE doped TiO 2 ER fluids is also be observed. In particular, the RE/Ti mole ratio has a significant influence on the dielectric properties, the maximum of perrimitivity and loss tangent can be observed when RE/Ti mole ratio is about 0.1. The comparison between dielectric and rheological properties shows that the difference of ER effects between modified and pure titania based ER fluids is because of the change of dielectric properties due to rare earth. The different temperature dependence of dielectric properties can explain the different temperature effects between RE doped TiO 2 ER fluids and pure TiO 2 ones.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2001年第5期514-517,共4页
Journal of Functional Materials
基金
国家自然科学基金重点资助项目 (59832 0 90 )
关键词
电流变液
稀土
介电性能
流变学性能
二氧化钛
electrorheological fluids
titania
rare earth
dielectric properties
rheological properties
