An investigation on the phae inversion behavior of polyethersulfone PES in ternary phase systems

Phase diagram has a significant role on assessing polymeric membranes phase tr ansition and can provide useful guidline about the formation of membranes and morphology. Besid es, liquid–liquid (L–L) phase separation is conducted to investigate how polymeric membrane mor phology change.Polyethersulfone is used as one of the most important polymeric materials with hi gh chemical nd thermal stabilities for membrane fabrication. Accordingly phase transition beh aviour of PES is investigated by attention on L-L demixing, vitrification and also the binodal and spinodal curve. Results reveal that changing the content of PES solution components have d irect effects on membrane structure. Incresing polymer concentration which causes an ea rly vitrification suppresses the growth of macrovoids and changing channel like structureto finger like configuration. Instantaneous L-L demixing leads the system to the formation of macrovoids.Moreover, wider miscibility region onternary diagram determine higher sol vent dissolution power. The results and findings in this investigation can be used for analysis th e effects of PES solution components on phase transition and predict its influence on morphology and structure of membrane.

Keywords:

PES , phase diagram , morphology , L -L demixing