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采用平均粒径为300 nm的Al2O3粉体,通过超声分散配制成稳定的制膜液,基于Hagen-Poiseuille和Darcy方程的理论计算,选择在平均孔径为1μm的载体上进行浸浆涂膜,经一次涂覆制备出无粗孔缺陷的Al2O3微滤膜.研究表明,制膜液的固含量、黏度、浸浆时间对膜厚有重要影响.当超声时间在20 min以上,膜层厚度大于40μm,烧结温度为1 050℃,制备的微滤膜平均孔径为100 nm,最大孔径为300 nm左右,孔径分布窄,渗透率在4 000 L/(m2·h·MPa)左右.进一步以该微滤膜作为底膜,制备出了小孔径氧化铝(Al2O3)超滤膜和氧化锆(ZrO2)纳滤膜.平均孔径为1μm的支撑体大大简化了纳滤膜的制备工艺流程,降低了能耗,提高了陶瓷纳滤膜的实际应用价值.该工作为非对称管式纳滤膜的制备及产业化提供了简单高效的方法.

The alumina with average particle size of 300 nm was used to prepare the stable dispersion after ultrasonic treatment,and then was dip-coated on the inner side of the substrate with pore size of 1 μm (based on the Hagen-Poiseuille and Darcy equation).After specific thermal treatment process,the defect free microfiltration membranes without obvious macropore were fabricated by one step.The results showed that the solid content of the dispersion,viscosity and the dipping time had great effect on the membrane thickness.When the time of ultrasonic treatment was over 20 min,the membrane thickness was over 40 μm and the sintering temperature was 1 050 ℃,the average pore size of microfiltration membranes was 100 nm and the maximum pore size was around 300 nm.The permeability was about 4 000 L/(m2 · h · MPa).Subsequently,the microfiltration membranes as sub-layers were applied to the fabrication of the ultrafiltration and nanofiltration membranes.The substrate with pore size of 1 μm greatly simplified the nanofiltration membrane preparation process,reduced the energy consumption,and improved practical application value of the ceramic nanofiltration membranes.This work provided an easy and cost-effective technique for the preparation and scaling-up of asymmetric tubular nanofiltration membranes.