| In this study, Al(OH)3 precipitate was prepared using AlCl3·6H2O as raw material. As-prepared Al(OH)3 precipitate was dispersed in organic solvent and water by ultrasonic vibrations, then stirred by magnetic stirrer and kept a proper temperature to obtain Al(OH)3 sol. By adjusting pH value of the Al(OH)3 sol in order to keep the stability of the sol system, a transparent and stable Al(OH)3 sol was prepared. The Al(OH)3 sol behaves non-Newton hydromechanics characteristic. The main factors that affect the stability of the Al(OH)3 sol was investigated. The results showed that the stability of the sol depended on concentration, dispersing time, heating temperature and pH.of the sol.Theγ-Al2O3 microporous films were prepared by sol-gel method, and the composition, microstructure and morphology of theγ-Al2O3 films.were characterized by DTA-TGA, BET, SEM. It was investigated that the effect of drawing speed, dipping time and coating times on the film thickness and adhesion to the substrates. It was found that the influence of drawing speed on thickness of films is different from the normal disciplinarian because of the non-Newton hydromechanics characteristic of Al(OH)3 sol. The thickness of films has a maximal value when the drawing speed increased 4.6-4.8cm/min. The influences of different peptizators on the surface morphology of thin films were also investigated in this paper. The influences of various adding amount of PEG on the structure of macro pores in the films were discussed, the comprehensive analyses were carried on the porous microstructures and amount of pores of macro and micro pores in films.In addition, theγ-Al2O3 films were prepared on the substrates beforehand coated with the TiO2 films, and the oxygen sensitivity properties of the compound films were studied. Moreover, it was investigated that the effect of noble metal Pd modification by different methods on the oxygen sensitivity properties of the films. The results showed that the noble metal modification could only improve the oxygen sensitivity properties of TiO2 films and had no effect on the protecting properties of theγ-Al2O3.
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