掺碳二氧化钛的制备和其电流变性质

Preparation and Characterization of Carbon-Doped Mesoporous TiO_2 Elctrorheological Fluid

采用十二烷基胺（ＤＤＡ）做模板合成了二氧化钛颗粒，并在氮气流中以不同温度碳化制出了掺碳的二氧化钛．掺碳二氧化钛的结构由透射电子显微镜（ＴＥＭ）、氮气吸附－脱附等温线、ＸＲＤ、ＸＰＳ等表征．掺碳二氧化钛颗粒的电镜照片显示颗粒中存在不规则孔，粒径大小为１３０～２００ｎｍ；氮气吸附－脱附等温线表明这些符合Ⅳ型等温线的颗粒存在介孔；ＸＲＤ显示在６７３Ｋ和８７３Ｋ碳化的二氧化钛是锐钛型结构；ＸＰＳ分析显示碳主要分布在粒子的表面．ＤＤＡ和二氧化钛的摩尔比在０．０４９～０．０９２，并在６７３Ｋ碳化的掺碳二氧化钛粉末分散在石蜡油中形成无水电流变液，因为在粒子表面的碳有合适的电导率，所以表现出很强的电流变效应．

The carbon-doped TiO2 particles via the route of synthesis of mesoporous TiO2 using dodecylamine (DDA) as a template and carbonization at different temperatures in flowing N-2 were prepared. The structures of the carbon-doped TiO2 were investigated by TEM, N-2 adsorption-desorption isotherm measurements, XRD and XPS. The TEM photographs of carbon-doped titania show disordered porous particles with size range from 130 to 200nm. The N-2 adsorption-desorption isotherm reveals the existence of mesoporosity in these materials with a type IV isotherm. The XRD patterns indicate that carbon-doped titania particles carbonized both at 673K and at 873K are anatase structures. The XPS analyses suggest that the carbon mainly distributed on the surface layer of the particle. The anhydrous electrorheological (ER) fluid composed of carbon-doped titania powders dispersed in paraffin liquid shows an intrinsic ER effect. The elctrorheological results show that the carbon-doped TiO2 particles synthesized with DDA/TiO2 mole ratio around 0.046 to 0.092 and carbonized at temperature around 673 K exhibit higher ER activities due to their proper conductivity caused by the carbon on the surface of the particles.