Prediction of swelling behavior of polymeric membranes in solutions using UNIF AC-related activity coefficient
- 化学化工－已发表论文 
[中文文摘]根据Vrentas-Duda自由体积理论,结合基于UNIFAC活度系数模型,在较宽的浓度范围内预测了聚合物膜在溶液中溶胀行为。用UNIQUAC方程计算液相中组分的活度,考虑了温度对模型方程中二元交互作用参数的影响。对水/乙二醇(EG)/聚乙烯醇(PVA)膜体系,三个不同温度60℃、70℃和80℃下计算结果和实验数据基本一致。模型方程中自由体积部分影响较大,考虑聚合物的粘弹性贡献对预测结果有一定改进。［英文文摘］In the frame of phase equilibrium the chemical potential of component in liquid phase equals that in polymer when sorption-desorption equilibrium was reached in the solvent/polymer mixture system. Using a simple activity coefficient model in conjunction with the Vrentas-Duda free volume theory, the swelling behavior of polymeric membrane in small molecular solvents was then predicted for the system of H2O/EG/PVA over a wide range of concentrations. The activity of solvents in liquid phase was estimated by modified UNIQUAC mode equations with temerature-dependent binary interaction parameters, while that in the polymeric membrane phase was predicted by Entropic-FV activity model equation being involved with free volume contribution which cannot be negligible in olymeric system.The estimations consist with experimental data at three temperatures of 60℃,70 ℃and 80℃.It is found that the Entropic-FV mdel id a suitable alternative to the Flory-Huggins equation for prediction of the swelling characteristic of polymeric membranes.The estimations were imroved by taking elastic effect into consideration.The research can be used for polymerec membrane material selection.