Flory-Huggins Based Model to Determine Thermodynamic Property of Polymeric Membrane Solution

Flory-Huggins (F-H) model has been widely used to analyze the thermodynamic behavior of polymeric membrane solution during the formation of membrane structure in a phase inversion process. The F-H model involves concentration and binary interaction parameter of components in membrane solution. Those parameters are used to calculate the composition of membrane solution at equilibrium which is then plotted on ternary diagram known as a binodal curve. The binodal curve is used to determine the type of demixing of the polymeric membrane solution and to predict the structure of resulted membrane. Several modifications of F-H model have been conducted in relation to composition (ternary or quaternary) and temperature of the membrane solution. In this paper, the development of F-H model used in designing polymeric membrane by phase inversion method, particularly immersion precipitation method, will be reviewed. The structure and performance of membranes that are governed by the thermodynamic property of the membrane solution based on F-H model will be discussed.