分散剂对二氧化钛包膜的影响研究

Research on the Influence of Dispersants on Coating of TiO_2

金红石型二氧化钛浆料pH值在9．0—10．0时，Zeta电位最大，在水中的分散性最好。探讨了硅酸钠、六偏磷酸钠、焦磷酸钠和磷酸二氢铵作为分散剂时，包膜过程的黏度变化情况，发现硅酸钠和六偏磷酸钠作为分散剂时体系黏度最低。利用硅酸钠作为分散剂，加入量为0．15％，一次性加入时，包膜过程体系黏度最低。采用比表面积和扫描电镜能谱对包膜产品表面成分的分析可知，包膜过程黏度低时，包膜剂在二氧化钛表面沉积比较均匀、致密。

With a pH value of 9.0 to 10.0, Zeta potential of ruffle titanium dioxide slurry reaches the maximum value, and the titanium dioxide has the best dispersion property in water. In this paper, the changes of viscosity in the coating process were studied as sodium silicate, sodium hexametaphosphate, sodium pyrophosphate, or ammonium dihydrogen were used as dispersants respectively. The results show that the slurry has lowest viscosity by taking sodium silicate or sodium hexametaphosphate as dispersant, and when sodium silicate is added at an amount of 0.15% all at once, the slurry＇ s viscosity is the lowest in coating process. Moreover, BET and SEM-EDS analyses on surface compositions of coated titanium di- oxide indicate that with lower slurry viscosity during the coating process, coating agents will deposit more evenly and compactly on the surface of TiO2.