锐钛矿型TiO_2多孔薄膜的室温制备及其机理研究

Room-temperature preparation and formation mechanism of porous anatase TiO_2 film

为在低温条件下制备多孔性TiO2薄膜,采用具有锐钛矿晶粒的TiO2溶胶与苯丙乳液混合制得涂膜液,通过浸渍提拉法制备薄膜,利用甲苯选择性地将薄膜中的苯丙乳液粒子溶解去除,制备出锐钛矿型TiO2多孔薄膜.使用扫描电镜(SEM)、透射电镜(TEM)、傅里叶变换红外光谱(FTIR)以及Zeta电位等分析测试方法对其制备机理进行了探讨.结果表明,TiO2溶胶与苯丙乳液混合后,陈化时间的延长有利于TiO2胶粒通过静电、氢键作用在苯丙乳液粒子表面形成吸附层,从而改变涂膜液的成膜性,形成较为密集、且均匀分布的岛状多孔结构,在此基础上经两次涂膜,即可获得具有致密孔洞的TiO2多孔薄膜.

A solution consisting of styrene-acrylate emulsion and anatase TiO2 colloidal particles was prepared in order to prepare crystalline TiO2 film with well porosity at low temperature. The films were obtained from resultant solution by a dip-coating technique, and styrene-acrylate spheres were preferentially dissolved in toluene, then the porous anatase TiO2 films were formed. Transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, Fourier transform infrared spectra （FTIR） and Zeta potential test were adopted to analyze the formation mechanism of TiO2 porous films. The styrene-acrylate spheres were coated with the TiO2 colloidal particles via electrostatic effect and hydrogen bond interactions with theincrease of aging time, thus the film-forming capability of the solution was changed. The poor film-forming capability results in the formation of the porous structure with dense, homogeneous island morphology. Then the TiO2 porous films with dense pores can be obtained after two coating-dissolving cycles.