TiO2的有机改性及其电泳性能

以改性的TiO₂粒子为显色粒子，四氯乙烯为分散介质，油溶红为染料，加入分散剂制备了电泳显示液。选用不同类型的有机表面活性剂和硅烷偶联剂对纳米TiO₂粒子进行表面改性。用红外光谱（FT-IR）表征了改性粒子的表面组成和结构，并通过透射电镜（TEM）观察了粒子的形态、粒径及分散情况。采用静态沉降法考察了改性后的粒子在四氯乙烯中的分散稳定性，并利用自行设计的电泳仪对粒子的电场响应特性进行了测试。结果表明，用阴离子表面活性剂十二烷基苯磺酸钠(SDBS)改性的粒子其分散稳定性和带电性最好。随后探讨了SDBS用量和反应时间对粒子分散性和带电性的影响，得到改性的最佳工艺条件为：改性剂用量为TiO₂含量的15%，反应时间为1h。改性后的粒子分散性和带电性有明显的提高，粒子对电场有可逆响应且具备一定的双稳性。

Organic surface modification of titanium dioxide and electrophoretic properties of the resulting materials

To prepare stable electrophoretic ink (E Ink) contains titanium dioxide particles, oil soluble red, dispersant and tetrachloroethylene (TCE), the modification of organic materials onto the particle surface was investigated. Modified particles were characterized by measurement of Fourier transform infrared spectroscopy (FT-IR) to confirm the composites and structures. The electrophoretic properties of sample in TCE were investigated by static sedimentation experiment and electrophoresis instrument. The type of organic materials used for the surface modification influence dispersibility and charge property of particles. On the whole, organic modified particles especially modified by anionic surfactant show better properties. The process conditions were investigated in detail using SDBS as the modifier. The results indicate the settle time of modified TiO₂ can last more than 200h with the response time to 30s in optimized modifying condition that the proportion of surfactant is 15% and reaction time is 1 hour which means SDBS modified TiO₂ is suitable for electrophoretic particles.