Abstract: A modified free - volume diffusion model for binary aqueous mixtures in pervapo-ration was developed on the basis of free -volume diffusion theory. Two coupling coefficients were introduced to describe the coupling effect of diffusion for nonideal system in pervapora-tion membrane. Combined with the membrane phase concentrations which were calculated from experimental adsorption data of four aqueous solutions in polyimide (PMDA -ODA) membrane, the experimental pervaporation data of the four mixtures were correlated with this model, good agreement was obtained between the calculated and experimental values.

摘要： 在自由体积扩散理论的基础上,提出了渗透蒸发过程中二元水溶液在聚合物膜中扩散的修正自由体积模型。模型中定义了2个共存因子,用以描述非理想物系在渗透蒸发膜扩散过程中的共存效应。结合4种水溶液在聚酰亚胺(PMDA-ODA)膜中的吸附实验数据所计算的膜相浓度,用本模型拟合了上述物系的渗透蒸发实验数据,获得较一致的结果。