TiO_2纳米管阵列膜的制备及结构研究

Fabrication and Microstructure of TiO_2 Nanotube Arrays Membranes

描述了在含不同浓度NH4F的2%H2O(体积分数,下同)和乙二醇溶液中,在氧化钛片上获得管尺寸分布一致的TiO2纳米管阵列膜。在不同电压、不同NH4F浓度电解液的条件下,进行膜的管尺寸及厚度研究,利用SEM评价膜的形貌。结果显示,片状膜为平行纳米管阵列组成的膜,纳米管尺寸范围宽、尺寸分布一致。管尺寸在15～128nm,膜厚可达360μm。应用的电压越高管尺寸越大,电解液中NH4F浓度增加导致管尺寸稍微减小。还观测到,NH4F浓度的增加,导致片状膜的厚度显著增加。采用无水乙醇多次清洗膜,并迅速用脱脂棉吸附膜上的溶液,在鼓风干燥箱中100℃,热处理1h,可有效解决膜卷曲的问题。

This work describes the fabrication of TiO2 nanotube array membranes with uniform tube size distribution by anodization of titanium flat sheets in ethylene glycol with 0.55%NH4F＋1.0%H2O and with 0.25%NH4F＋2.0%H2O（volume fraction）. The membranes were investigated for characteristics such as tube size, thickness by varying applied voltage and ammonium fluoride concentration of electrolyte. Morphology of the membranes was examined using scanning electron microscopy. Results showed that fiat sheet membranes having wide tube size and uniform tube distribution with parallel channel arrays were obtained. The tube sizes（inner） ranged from 15 to 128 nm and the wall thicknesses was as high as 360 μm. It was found that the tube size increased in direct proportion with the applied voltage, and the tube size little decreased with the ammonium fluoride concentration increasing. It was also observed that increase in ammonium fluoride concentration remarkably increased tubular membrane thickness. With anhydrous ethanol cleaning repeately rinsed membranes, then using absorbent cotton made membranes quickly dried and thermal treatment its in an air environment at 100℃ for and heat treatment at 100℃ for 1 h effectually solved the problem of membrane curl. By anodic titania technology, robust ceramic tubes with uniformly distributed tube structure and parallel nanochannels of lengths and sizes practical for industrial applications were reliably produced in quantity.