膜/液界面浓度极化现象的介电解析

Dielectric Analysis of the Concentration Polarization Phenomena at Membrane/Solution Interface

对由强、弱荷电膜和溶液构成的膜／液非均匀体系，在10－107Hz频率范围进行了介电测量，在直流偏压下，该体系显示了二个显著的介电弛豫．利用具有电导率分布相，即浓度极化相的介电理论对强行电的离子交换膜的结果进行了介电解析，从实验上测得的介电参数求出了反映膜／液界面浓度极化层构造的参数，讨论了该体系产生介电弛像的原因、说明了介电理论的合理性，并提出了膜／液界面体系产生介电弛豫现象的可能机理．

A dielectric measurements were carried out over the frequency range 10 ~107 Hz for the systems comprising strong, weak charged membranes and solution. A distinct double dielectric relaxation was observed under application of d.c. bias voltage. The data on the double relaxtion for cation-exchange membrane were analyzed by using a dielectric theory fbr concentration polarization layer(CPL), the strcture parameters of the layer and phase parameters of the two adjining aqueous phases were obtamed from dielectric parameters observcd. The cause of dielectric relaxation was discussed in detail.The results of simulation basis of dielectric theory of CPL made in previous study are shown to be reasonable, and a high possibility in respect to the origin of the dielectric relaxation was suggested by the experimerts.