纳米TiO2表面吸附聚乙二醇及其分散稳定性的研究

通过四氯化钛水解法制备纳米TiO2，讨论聚乙二醇(PEG)在其水悬浮体系中的吸附行为．IR和吸附实验结果表明：纳米TiO2通过氢键吸附PEG，其表面吸附行为与PEG浓度、PEG分子量、pH值和晶粒尺寸等因素相关．吸附PEG以后，纳米TiO2颗粒的表面电荷和(电位发生变化．悬浮体系吸光度的变化和TEM分析表明：纳米TiO2吸附PEG后，增加了颗粒间的空间位阻作用，有效地阻止了纳米TiO2的团聚；但若PEG加入量达到过饱和，反而会破坏纳米TiO2的分散稳定性．

Polyethylene Glycol Adsorption Behavior on Nanoparticulate TiO2 and Its Stability in Aqueous Dispersions

Nano-sized TiO2 particles with anatase structure were synthesized by hydrolysis of titanium tetrachloride. The adsorption of polyethylene glycol (PEG) on to the particle surfaces was investigated in aqueous suspensions. Infrared adsorption spectra and adsorption experimental results indicated the adsorption behavior was related to PEG concentration, pH, molecular weight and crystalline .size. The measured surface charge and Zeta potential of TiO2 particles varied distinctly after PEG adsorption. The changes of the absorbances and TEM analysis showed that the adsorption of PEG onto the surface of nano particles provided a high degree of steric stabilization and remarkably improved the stability of as-formed suspension against flocculation in water. While supersaturated adsorptions of PEG inversely destroyed the stability of the dispersion of nano-sized TiO2 particles.