Developement of New Polymer Membranes for Separation

以甲基丙烯酸2，3-环硫丙酯（ETMA）-甲基丙烯酸（MAc）、ETMA-甲基丙烯酸2-磷酸乙酯（MP）和ETMA-2-丙烯酰胺-2-甲基丙磺酸（叔丁基丙烯酰胺磺酸）（TBAS）共聚物制备阳离子交换膜。通过使用含有酸（左侧）和碱金属或碱土金属离子（右侧）的系统来研究碱金属离子通过膜的传输。所有这些共聚物膜传输碱金属离子从右侧到左侧反对他们的浓度梯度。为了获得具有克服其浓度梯度的高的金属离子传输能力的膜，必须（1）在膜可以使用而不会由于高溶胀而破裂的组成范围内增加膜中载体如羧基、磷酸基或磺酸基的含量，（2）使膜致密化，使<H^+>和<OH^->不能通过浓度梯度简单地扩散通过膜;（3）抑制阴离子如<Cl^->向膜内的扩散。碱金属离子通过ETMA-MP和ETMA-TBAS共聚物膜的迁移率高于通过ETMA-MAc共聚物膜。由于ETMA-MAc共聚物膜的物理和化学结构容易被紫外光照射改变，因此，紫外光照射可以提高ETMA-MAc共聚物膜的碱金属离子透过率、透过率以及碱金属离子之间的选择性透过率。在这个系统中，细胞膜的一侧是酸性的，另一侧是碱性的，酸性一侧的初始<H^+>浓度对细胞膜的转运有很大影响。

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.