Fundamental Research on Structure and Permeation and Separation Characteristics of Polymer Membranes for Separation of Organic Liquid Mixtures

通过改变成膜条件，制备了壳聚糖(Chito)、聚(二甲基硅氧烷)(PDMS)、聚[1-(三甲基硅基)-1-丙炔](PTMSP)和甲基丙烯酸甲酯-二甲基硅氧烷(MMA-g-DMS)等不同化学和物理结构的复合膜。研究了有机液体混合物膜分离技术中的渗透汽化(PV)、蒸散量(EV)和不同渗透条件下改进的温差控制蒸散量(TDEV)对乙醇水溶液的渗透分离特性。在壳聚糖膜中，PV和EV都表现出水的渗透选择性，且EV的渗透选择性高于PV。它们的渗透选择性明显取决于壳聚糖膜上基于氢键的自由亲水基团的程度。在聚二甲基硅氧烷膜中，PV膜表现出对乙醇的选择性，将该膜应用于TD…时，膜对乙醇具有选择性料液温度与膜环境温差越大，EV越大，乙醇对膜的选择性越高。在PTMSP膜中，PV和TDEV与PDMS膜一样具有乙醇渗透选择性，但PTMSP膜的渗透速率和乙醇渗透选择性大于PDMS膜。结果表明，PTMSP膜的渗透速率随膜厚的减小而显着增加，乙醇选择性与膜厚度无关。在MMA-g-DMS膜的PV中，渗透选择性显著地依赖于MMA-g-DMS共聚物中DMS单元的含量。也就是说，DMS单位含量小于36mol%的膜具有水渗透选择性，大于36mol%的膜具有乙醇渗透选择性。通过对MMA-g-DMS膜的差示扫描量热法测量和透射电子显微镜观察，揭示了膜选择性的差异，并进一步用渗透理论方程进行了分析。较少

Chitosan (chito), poly (dimethylsiloxane) (PDMS), poly [1- (trimethylsilyl) -1-propyne] (PTMSP) and methyl methacrylate-dimethylsiloxane (MMA-g-DMS) membranes with different chemical and physical structures were prepared by changing conditions of membrane preparation. Characteristics of permeation and separation for aqueous ethanol solutions were studied by pervaporation (PV) which is one of membrane separation techniques for organic liquid mixtures, evapomeation (EV) which was developed by head investigator and coworkers, and themperature difference controlling evapomeation (TDEV) which was improved EV under various permeation conditions. In the chito membrane, both PV and EV showed water-permselectivity and the permselectivity in EV was higher than in PV.Their permselectivity significantly depended on a degree of free hydrophilic groups based on hydrogen bonds of the chito membrane. In the PDMS membrane, ethanol-permselectivity was shown in PV and when this membrane was applied to TD … More EV,ethanol-permselectivity was increased with bigger difference between the temperatures of the feed solution and membrane surroundings. In the PTMSP membrane, both PV and TDEV had ethanol-permselectivity as well as the PDMS membrane, but permeation rate and ethanol-permselectivity in the PTMSP membrane were greater than those in the PDMS membrane. It was found that the permeation rate was remarkably increased with decreasing thickness of the PTMSP membrane and ethanol-permselectivity was kept constant regardless of the membrane thickness. In PV of MMA-g-DMS membrane, the permselectivity significantly depended on the DMS unit content in the MMA-g-DMS copolymer. Namely, the membranes less than DMS unit content of 36mol% showed the waterpermselectivity and those of moer than 36mol% had the ethanol-permselectivity. These difference of the permselectivity was revealed by measurements of difference scanning calorimetry and observations of transmission electron microscope of the MMA-g-DMS membranes and furthermore analyzed by theoretical equation of the permeation. Less