掺碳二氧化钛的制备和其电流变性质

摘要

The preparation of carbon-doped TiO2 particles via the route of synthesis of mesoporous TiO2 using dodecylamine（DDA）as a template and carbonization at different temperature in flowing N2 is presented．The structures of the carbon-doped TiO2 were investigated by TEM，N2 adsorption－desorption isotherm measurements，XRD and XPS．The TEM photographs of carbon-doped titania show disordered porous particles with size range from 130 to 200 nm．The N2 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 873K are anatase structures，but the crystalline size of the sample carbonized at 673K is smaller than that of the sample carbonized at 873K．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 0．05 to 0．10 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．%采用十二烷基胺(DDA)作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。掺碳的二氧化钛的结构由透射电子显微镜(TEM)、氮气吸附－解吸等温线、XPS等表征。掺碳二氧化钛颗粒的电镜照片显示有不规则孔，粒径大小为130～200nm。氮气吸附－解吸等温线表明：这些有着IV型等温线的颗粒存在介孔。XPS分析显示碳主要分布在粒子的表面。掺碳的二氧化钛粉末分散在石蜡油中形成无水电流变液，表现出很强的电流变效应。DDA和二氧化钛的物质的量比在0．05～0．10并在673K碳化的掺碳二氧化钛表现出很强的电流变效应，主要是因为在粒子表面的碳有合适的电导率。