TiO2表面包覆SiO2和Al2O3的机理和结构分析

在二氧化钛的表面上包覆一层保护膜,使二氧化钛的表面和周围介质之间产生屏障,从而降低二氧化钛的光化学活性,有利于提高二氧化钛的分散性、耐光性、耐候性和抗粉化性.

Mechanism and Structure Analysis of TiO2 Surface Coated with SiO2 and Al2O3

Photochemical activity of TiO 2 can be reduced through surface coating, which favors to increase dispersiveness, weather resistance and antipulverization. The binary coating process of Si and Al to TiO 2 was studied experimentally. The isoelectic point of TiO 2 in seriflux was measured as pH was equal to 3 6. Maximum Zeta potential can be got at pH 10 around, which favors to dispersion of particles. Studies on the aggregation rate of Si and Al indicate that, when pH has a value between 9 and 10, the aggregation rate of silicon acid is small, which favors to form homogeneous and compact membrane, so optimal coating pH value is between 9 and 10. According to the difference of 2 p orbital electron binding energy of Ti in XPS before and after being coated, it can be inferred that Si and Al in coating layer combine to TiO 2 surface through chemical bond.