thermodynamic evaluation of polymeric membrane solution: (poly propylene fumarate/(graphene oxide/pluronic f-68))/2-pyrrolidone (2p)/water quaternary system assessment

In this study, a thermodynamic behavior of the quaternary system of (poly propylene fumarate/ (graphene oxide/ pluronic f-68))/2-pyrrolidone (2p)/water was evaluated. the binodal and spinodal curves plotted using by flory–huggins theory and compared with experimental data. the results showed that at low value of binary parameter, a high interaction is existed between two components in ternary system. the ternary system at positive ternary interaction parameter (g123) indicates a small miscible region and small changes in water content of the polymer-rich phase. at the negative values of g123, there is a high miscibility in ternary system. in quaternary system, when g1234 is positive, the binodal curve shifts to the (polymer/additive)/ solvent axis. the membrane formation depends on the thermodynamic behavior of casting solution. by increasing the additive in casting solution up to 4wt.%, the de-mixing process was accelerated. hence, a membrane was formed with high porosity. when additive content was increased to more than 4 wt%, dynamic viscosity of casting solution was responsible to the phase separation rate decreasing.