渗透汽化过程中膜的溶胀行为研究

以壳聚糖和硫酸交联壳聚糖膜为研究对象，详细考察了两种膜在乙醇──水体系中的溶胀特性．实验发现，在溶胀过程中存在强烈的耦合效应．为了分析溶胀过程中的耦合效应，定义了组分在膜中的活度与体积分率的关系，同时，建立了溶胀过程参考态的概念，用以描述单个组分与膜之间相互作用对活度系数的贡献．在溶胀过程中，组分的活度系数相对于参考态活度系数的差异反映了膜内组分间耦合效应的影响．水的溶胀特性基本受控于水与膜之间的相互作用关系，对于乙醇而言，其溶胀特性强烈地受水在膜中溶胀特性的影响．

A STUDY ON THERMODYNAMIC SWELLING PROCESS IN PERVAPORATION

The thermodynamic swelling characteristics of chitosan membrane and H_2SO_4 crosslinking chitosan membrane in water-ethanol mixture were studied.Thermodynamic swelling distribution relationship showed there existed strong coupling effect in the themodynamic sewlling process.In order to analyze the coupling effect in the thremodynamic swelling process,the relationship between the activity and volume fraction of each component within the membrane was defined.And the concept of reference state in the thermodynamic swelling process which only considered the interaction between individual component and membrane matrix was also set up.The interaction between H_2O and the membrane matrix dominated the activity coefficient of H_2O within the membrane,But the activity coefficent of EtOH was dominated strongly by the coupling effect between H_2O and EtOH within the membrane because of existence of H_2O within th membrane