中空纤维陶瓷基渗透汽化复合膜制备及分离性能研究

发布时间：2018-02-25 07:00

  本文关键词： Al2O3中空纤维膜 渗透汽化 化学接枝 物理涂覆　出处：《南昌航空大学》2015年硕士论文　论文类型：学位论文

【摘要】：膜分离技术越来越广泛的应用于废水处理、石化分离、药物分离等领域。渗透汽化膜具有分离效率高,能耗低等优点,特别适合恒沸点、近沸点、有机/有机混合物的分离。高分离性能的膜材料一直是渗透汽化膜关注和研究的热点。本文利用无机材料和有机材料各自的优点,制备高充填密度的有机/无机中空纤维渗透汽化复合膜。将A12O3颗粒分散在PAN/DMAc溶液中,制得铸膜液,采用干湿相转化-烧结法制备长为25cm的Al2O3中空纤维膜管。用SEM对中空纤维膜胚和中空纤维膜的微观结构进行表征,PAN将Al2O3粉体粘结在一起形成中空纤维膜胚,经高温烧结后,得到孔径大小为2-8nm的A12O3中空纤维膜,孔径分布均一,纯水通量为5480 L·m-2·h-1.bar-1。用浸渍涂覆法和真空涂覆法制得PDMS/Al2O3中空纤维复合膜。浸渍涂覆法制得的复合膜的致密分离层只附着在中空纤维膜外表面,而真空涂覆法制得的复合膜的致密分离层充满了膜壁的孔穴。浸渍涂覆法制备的中空纤维复合膜对模拟发酵液中乙醇较好的回收效果:在料液温度为30℃,乙醇浓度为5wt%时,渗透通量最高可达425 g·m-2·h-1,乙醇的分离因子最高可达8.5。提高料液温度,有利于提高渗透通量,60℃时渗透通量最高为700g·m-2·h-1,乙醇的分离因子可达6.63。用浸渍涂覆法在Al2O3中空纤维膜外表面涂覆一层厚度为121μmTPU致密分离层,TPU和Al2O3中空纤维膜之间附着力好,无分层和脱落现象。TPU/Al2O3复合膜对水中乙酸乙酯具有较好的回收效果:(1)在料液温度40℃,乙酸乙酯质量分数为2wt%时,复合膜的渗透通量最高可达950g·m-2·h-1,分离因子最高可达12.3。Al2O3中空纤维膜用KH550处理后,再同GMA反应引入乙烯基,最后同丙烯酸单体接枝聚合,成功制得Al2O3-g-P(AA)中空纤维复合膜。FTIR分析表明,丙烯酸单体以化学键的形式接枝到Al2O3中空纤维膜上。SEM分析表明,Al2O3中空纤维膜外表面聚丙烯酸厚度为24.62μm。复合膜具有强烈的亲水性,对乙醇中微量水有很好的脱除效果:在乙醇浓度为99.5wt%,料液温度为60℃时,渗透通量最高为80g·m-2·h-1,分离因子最高可达60。
[Abstract]:Membrane separation technology is more and more widely used in wastewater treatment, petrochemical separation, drug separation and other fields. Pervaporation membrane has the advantages of high separation efficiency and low energy consumption, especially suitable for constant boiling point, near boiling point, etc. Separation of organic / organic mixtures. Membrane materials with high separation performance have been the focus of attention and research on pervaporation membranes. An organic / inorganic hollow fiber pervaporation composite membrane with high filling density was prepared. A12O3 particles were dispersed in PAN/DMAc solution to prepare the casting membrane liquid. Al2O3 hollow fiber membrane tubes with a length of 25 cm were prepared by dry-wet phase conversion sintering method. The microstructures of hollow fiber membrane embryos and hollow fiber membranes were characterized by SEM. The Al2O3 powder was bonded together to form hollow fiber membrane embryos by SEM, and then sintered at high temperature. A12O3 hollow fiber membrane with 2-8 nm pore size was obtained, and the pore size distribution was uniform. The pure water flux is 5480L 路m-2 路h-1.bar-1. The PDMS/Al2O3 hollow fiber composite membrane is prepared by impregnation coating and vacuum coating. The dense separation layer of the composite membrane obtained by impregnation coating method only adheres to the outer surface of the hollow fiber membrane. However, the dense separation layer of the composite membrane prepared by vacuum coating method is filled with holes in the membrane wall. The hollow fiber composite membrane prepared by impregnation and coating method has a better recovery effect on ethanol in the simulated fermentation broth. When the temperature of the liquid is 30 鈩，

本文编号：1533423