【作者】 覃操； 王亭杰； 金涌；

【Author】 QIN Cao, WANG Ting-Jie, JIN Yong (Department of Chemical Engineering, Tsinghua University, Beijing 100084, China)

【机构】 清华大学化学工程系；

【摘要】 在不同pH值和温度条件下,研究了TiO₂颗粒表面包覆Al₂O₃纳米膜的适宜工艺条件。采用透射电镜、ζ-电位仪研究了TiO₂颗粒表面包膜过程的特征和包覆前后颗粒表面电动力学特性的变化。分析表明,通过颗粒表面双电层的静电引力和异相成核作用,水解形成的Al（OH）₃溶胶在TiO₂颗粒表面沉积,实现连续均匀的纳米膜包覆。通过X射线衍射分析确定纳米膜的组成为拟薄水铝石,通过红外光谱和X射线光电子能谱分析,推断TiO₂颗粒与Al₂O₃包覆层界面形成Ti-O-Al的键合结构。更多还原

【Abstract】 Some factors affecting TiO2 surface coating with A1203 film at nano-scale for the improvement of its pigmentary performance were studied. Effects of different pH and temperatures were investigated in the experiments and the optimum conditions for Ti02 particle coated with hydrous alumina film were determined to be pH 5.7-6.3 and the temperature 50-60℃. The deposition mechanism of A1(OH)3 on the surface of TiO2 particles was also analyzed. Through the analysis of transmission electron microscope (TEM) images and zeta-potential analyzer, it is shown that a uniform film of hydrous alumina on TiO2 particles is achieved and the zeta-potential of TiO2 particles was changed remarkablly after coating. The A1(OH)3 gel was analyzed by X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). It is shown that the hydrous alumina film was in the form of pseudo-boehmite. From the analysis of Fourier transform infrared spectrometer (FT-IR) and X-ray photoelectron spectroscopy (XPS), it is inferred that Ti-O-AI bonds form at the interface of TiO2 particles and A1(OH)3 film.更多还原