ION AND ELECTRON TRANSPORT ACROSS ENZYME IMMOBILIZED BIPOLAR MEMBRANE

包括电子在内的物质通过膜的流动是由电化学势的差异、其他物质的流动和化学反应引起的。众所周知，如果体系是由对称结构组成的，化学反应是标量的，那么化学反应就不应该与流动耦合。然而，如果体系的结构是不对称的，则它是可以耦合的。研究了一种酶固定化双极膜，该膜具有不对称的结构，在膜的两边都有正负电层，它们之间含有酶。用尿素-尿素酶体系讨论了转运和化学反应的耦合机理。在分析过程中，我们发现弱电解质在带电薄膜中的传输机理还没有从理论和实验上系统地研究出来。为了阐明这些问题，我们首先研究了Na_2SO_3的渗透系数随膜外溶液浓度的变化。其次，考虑Na_2SO_3渗透的结果，从理论上研究了弱电解液在带电薄膜上的迁移现象，方程中必须包含解离平衡常数。理论结果较好地解释了输运和化学反应的耦合现象。

The substance flow including electron across a membrane is induced by the difference of electrochemical potential, the flow of other substances and the chemical reaction. It is well known that no flow should be coupled with chemical reaction if the system is composed of symmetric structure because chemical reaction is scalar. lt,however,could be coupled if the structure of the system is asymmetric.An enzyme-immobilized bipolar membrane, which has an asymmetric structure consisting of positively and negatively charged layers on each side of the membrane and is containing enzyme between them, was studied. The coupling mechanism of the transport and chemical reaction was discussed using urea-urease system. In course of this analysis, we found that the transport mechanism of weak electrolyte across charged membrane was not systematized yet theoretically and experimentally. To clarify these problems we firstly investigate the permeability coefficients of Na_2SO_3 as a function of concentration of external solution of the membrane. Secondary the transport phenomena of weak electrolyte across charged membrane are investigated theoretically considering the result of Na_2SO_3 permeation, where the dissociation equilibrium constant has to be included in the equation. The theoretical results well explained coupling phenomena of transport and chemical reaction qualitatively.