Poly(vinylidene difluoride) (PVDF) is the main stream material for water treatment membrane. Thermally induced phase separation (TIPS) is frequently used as a manufacturing technology to produce a porous membrane. In phase separation technology, polymeric additives can be added to control the pore structure of the porous membranes. In this study, in order to clarify the functions of the polymeric additives such as Poly(ethylene glycol) (PEG) and Poly(vinyl pyrrolidone) (PVP) in the PVDF TIPS process, phase diagrams were prepared on TIPS process. In addition, cast films were prepared using dopes whose phase diagrams were prepared, and their surface structures were observed by SEM analysis. As a result, we clarified the mechanisms for controlling the pore structures of PVDF by selection of polymeric additives.
