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

通过改变膜制备条件，制备了不同化学和物理结构的壳聚糖（chito）、聚二甲基硅氧烷（PDMS）、聚[1-（三甲基硅氧烷）-1-丙炔]（PTMSP）和甲基丙烯酸甲酯-二甲基硅氧烷（MMA-g-DMS）膜。采用渗透汽化技术（PV）、蒸发技术（EV）和温差控制蒸发技术（TDEV）对乙醇水溶液的渗透和分离特性进行了研究。渗透汽化技术是有机液体混合物膜分离技术中的一种，蒸发技术是由首席研究员和同事共同开发的，而温差控制蒸发技术则是在不同的渗透条件下对EV进行改进的。在chito膜中，PV和EV均表现出对水的选择性，且EV的选择性高于PV。它们的过电选择性很大程度上取决于基托膜上基于氢键的自由亲水性基团的程度。PDMS膜在PV中表现出乙醇选择性，当膜应用于TD时，EV越多，乙醇选择性越高，进料液温度与膜环境温度差越大。在PTMSP膜中，PV和TDEV与PDMS膜一样具有乙醇选择性，但PTMSP膜的渗透率和乙醇选择性大于PDMS膜。结果表明，随着膜厚度的减小，渗透速率显著增加，且与膜厚度无关，乙醇选择性保持不变。在MMA-g-DMS膜的PV中，共聚物中DMS的单位含量显著影响了其过电选择性。DMS单位含量低于36mol%的膜具有水选择性，高于36mol%的膜具有乙醇选择性。通过差扫描量热法和透射电镜观察，揭示了MMA-g-DMS膜的过电选择性差异，并用理论渗透方程对其进行了分析。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