Developement of New Polymer Membranes for Separation

采用2,3-上皮甲基丙烯酸丙酯(ETMA)-甲基丙烯酸（MAc）、ETMA-2-甲基丙烯酸磷酸乙酯（MP）和ETMA-2-丙烯酰胺-2-甲基丙烷磺酸（叔丁基丙烯酰胺磺酸）（TBAS）共聚物制备阳离子交换膜。采用含酸（左）和碱或碱土金属离子（右）的体系研究了碱金属离子在膜上的转运。所有这些共聚物膜从右侧向左侧输送碱金属离子，违背其浓度梯度。为了获得对其浓度梯度具有高金属离子转运能力的膜，需要(1)在膜不因高溶胀而破裂的组成范围内，增加膜中羧基、磷酸基、磺酸基等载体的含量；(2)使<H^+>和<OH^->通过浓度梯度使膜致密，使其不能简单地通过膜扩散。(3)抑制<Cl^->等阴离子向膜内的扩散。碱金属离子通过ETMA-MP和ETMA-TBAS共聚物膜的输运量高于通过ETMA-MAc共聚物膜的输运量。紫外光照射可以改变ETMA-MAc共聚物膜的物理化学结构，从而提高了ETMA-MAc共聚物膜的输运速率、碱金属离子的输运分数和碱金属离子之间的选择性输运。在这个系统中，细胞膜的一侧是酸性的，另一侧是碱性的，运输受到酸性侧初始<H^+>浓度的显著影响。

Cationic exchange membranes were prepared with 2,3-epithiopropyl methacrylate(ETMA)-methacrylic acid(MAc),ETMA-2-phosphoethyl methacrylate(MP), and ETMA-2-acrylamide-2-methylpropane sulfonic acid(tertiary butyl acrylamide sulfonic acid) (TBAS) copolymers. Transporrt of alkali metal ions through the membranes was investigated by using the system containing acid(left side) and alkali or alkali earth metal ions(right side). All these copolymer membranes transported alkali metal ions from the right side to left side against their concentration gradient. In order to obtain the membrane with high ability of transport of metal ions against its concentration gradient, it was necessary to (1) increase the content of carrier such as carboxyl group, phosphoric acid group or sulfonic groups in the membrane in the composition range at which the membrane can be used without breaking because of high swelling, (2) make the membrane dense for <H^+> and <OH^-> not to diffuse simply through the membrane by the concentration gradient, and (3) depress the diffusion of anion such as <Cl^-> into the membrane. The transport of alkali metal ions through the ETMA-MP and ETMA-TBAS copolymer membrane is higher than that through the ETMA-MAc copolymer membrane. The transport rate, transport fraction of alkali metal ions , and the selective transport between alkali metal ions through the ETMA-MAc copolymer membrane could be increased by using the copolymer membranes irradiated with ultra violet light, because the physical and chemical structure of the membrane made of ETMA-MAc copolymer can be easily be changed by irradiation with ultra violet light. The transport in this system, where one side of the membrane in a cell was acidic and the other alkaline, was influenced significantly by the initial <H^+> concentration on the acidic side.