过滤成膜制备氧化铝中空纤维超滤膜

Preparation of Alumina Hollow Fiber Ultrafiltration Membrane by Filtering Coating

介绍了在α Al2 O3 中空纤维微滤膜上采用过滤成膜技术制备γ Al2 O3 超滤膜的方法 .应用热重分析、差热分析、X射线衍射和扫描电子显微镜等测试手段对膜的热稳定性、结构及形貌进行了表征 .扫描电子显微镜结果表明 ,采用过滤成膜方式制备的担载中空纤维超滤膜表面无针孔 ,无裂纹 .气体渗透实验进一步表明 ,所得中空纤维超滤膜完整、无缺陷 ,具有一定的气体选择性 .经 70 0℃焙烧后的膜在 0 3和 0 4MPa条件下对氮 /氩的分离因子分别为 1 133和 1 139,说明气体通过膜的扩散以Knudsen扩散传质为主 .用等温氮气吸附实验测定了非担载膜的孔径大小和分布 ,其比表面积为 2 2 8 9m2 /g ,最可几孔径约为 4 5nm .

The filtering coating method was introduced to prepare gamma-Al2O3 ultrafiltration membrane using alpha-Al2O3 hollow fiber microfiltration membrane as substrate. The thermostabitity, phase transformation, structure and appearance of ultrafiltration membrane were characterized by thermogravimetric analysis, differential thermal analysis, X-ray diffraction and scanning electron microscopy, respectively. The results showed that the gamma-Al2O3 ultrafiltration membrane with support prepared by filtering coating method is defect-free. The membrane is of gas selectivity, and the separation factors of nitrogen to argon are 1.133 and 1.139 at 0.3 and 0.4 MPa respectively. It was showed that the gas diffusion through the membrane is governed by Knudsen diffusion mechanism. The most probable pore diameter of an unsupported membrane after calcination at 700 degreesC is about 4.5 nm and its specific surface area is 282.9 m(2)/g characterized by nitrogen isothermal adsorption measurement.