以二氧化钛前驱体为基的电流变液的成分分析和机理研究

Composition analysis and mechanism approach of the electrorheological fluids based on the precursor of TO_2

制备了二氧化钛前驱体粉体,它具有优良的巨电流变效应,但不含一水草酸钙的成分.通过X射线衍射谱、扫描电子显微镜、电感耦合等离子体光谱仪和热失重-质谱联用仪等一系列实验手段,对二氧化钛前驱体粉体进行了表征,发现它是非晶形态的纳米粉体,其主要成分为TiOC2O4·2H2O和TiO(OH)2.由二氧化钛前驱体配置的电流变液具有与钛酸钙前驱体电流变液类似的温度特征,即当处理温度超过160℃后,电流变液的屈服强度会逐渐降低,至200℃后,巨电流变效应完全消失.通过对比分析发现,伴随上述巨电流变效应消失过程的化学反应是TiOC2O4·2H2O在加热过程中失去了结晶水.这些特征在所有钛酸盐系列的电流变液中均可观察到,因此我们推断TiOC2O4·2H2O是钛酸盐系列巨电流变液中的关键物质.

We synthesize the powder of the precursor of TiO2, which shows the giant electrorheological effect but does not include the component of CaC2O4.H2O. By use of X-ray diffraction, scanning electron microscope, inductively-coupled plasma spectrometer, themogravimetry-mass spectrum, etc, it is found that the precursor of TiO2 is amorphous powder with nanosize, and its components include TiOC2O4.2H2O and TiO（OH）2. The electrorheological fluid made by the powder shows a similar temperature characteristic to that made by the precursor of CaTiO3, i.e., when the powder is heated to the temperature above 160℃, the yield stress of the electrorheological fluid made by it decreases gradually, and when it is heated to 200℃, the giant electrorheological effect disappears completely. It is also found that the chemical reaction accompanies with the disappearance of the giant electrorheological effect is that the crystalized water in TiOC2O4.2H2O is volatilized in heating process. These characteristics can be observed in all electrorheological fluids made by the precursor of other titanate, so we conclude that TiOC2O4.2H2O is the key component for this series of giant electrorheological fluids.