陶瓷中空纤维担载有机共混渗透汽化脱水膜的制备及表征

Preparation and characterization of ceramic hollow fiber-supported blend membranes with high performance for the pervaporation dehydration

在多孔陶瓷中空纤维支撑体表面用浸渍-提拉法制备了致密、无缺陷的有机分离层,其中有机分离层是以马来酸酐交联的对水具有分离选择性的壳聚糖(CS)-聚乙烯醇(PVA)共混复合材料.采用扫描电子显微镜、溶胀度分析与渗透汽化性能测试等手段,系统地考察了支撑体孔径和不同CS和PVA共混比例对膜性能的影响.同时研究了进料液水含量和操作温度对乙酸乙酯脱水渗透汽化性能的影响.实验结果表明,该复合膜在乙酸乙酯渗透汽化脱水过程中表现出优异的分离性能,在操作温度50℃,料液水质量分数为3%时,CS共混比(质量分数)为60%的PVA-CS共混复合膜的渗透通量高达1 195g/(m2.h),对水的分离因子大于10 000.所制备的陶瓷中空纤维担载有机共混渗透汽化脱水膜将具备良好的商业应用前景.

Defect-free dense polymeric separation layer was fabricated on the surface of porous ceramic hollow fiber by dip-coating method. The separation layer is water-selective polymer prepared by blending poly（vinyl alcohol） （PVA） with chitosan （CS）. Scanning electron microscopy, swelling experiment and pervaporation test were used to systematically study the effect of pore size of the ceramic support and PVA -CS blending ratio on the pervaporation performance of the as-prepared composite membranes. The effects of feed composition and operating temperature on the pervaporation performance in ethyl acetate- water mixtures were also investigated. The results indicated that the composite membranes exhibited excellent pervaporation performance in dehydration of ethyl acetate, as the CS blending concentration is 600/00, the total flux was as high as 1 195 g/（m2 · h） and the separation factor was more than 10 000, with 3Y00 water in feed at 50℃.