纳米二氧化钛粒子分散性能的研究

以四氯化钛为原料，采用溶胶-凝胶法技术合成路线，获得了平均粒径为63nm的二氧化钛粉末。采用分散技术，不仅可以改善粒子的分散性能，而且对粒子的生长也起到一定的抑制作用。研究表明：(1)采用SDS作为分散剂时，其极性基团和非极性基团分别与水和纳米TiO2粒子相结合，从而阻隔了TiO2粒子的团聚，起到分散作用。(2)以稀土元素La作为分散剂，其独特的轨道结构，不仅扩大了能量吸收的范围，更重要的是它与TiO2形成的络合物，使其成为相对独立的小团体，而它本身很小的固溶度使其难于形成合金化组元，结果被释放出来，从而形成更小的纳米TiO2粒子，起到分散纳米TiO2粒子的作用，并同时抑制纳米TiO2粒子的生长。

Dispersity of Nanometer Titanium Dioxide

Nanosized TiO_2 powder was synthesized by a sol-gel method using TiCl_4 ethanol solution as a precursor. The dispersity of nano-titanium dioxide was studied. The results indicate that the dispersers such as sodium dodecylsulphonate (SDS) and rare-earth element La doping plays an important role in the dispersity of the particles and the growth of the grain. The SDS can hold back the agglomeration of the particles since SDS has polarity groups and non-polarity groups, which can make it link the TiO_2 powder at one side and H_2O at the other side. The rare-earth element La doping improves both the dispersity and the growth of the titania powder. The mechanism is that La has the special orbit structure, which could receive energy among the reaction, moreover, the formation of the La ligand disperses the TiO_2 powder better, and makes the particles smaller.