Morphology and performance of PVDF TIPS microfiltration hollow fiber membranes prepared from PVDF/DBP/DOP systems for industrial application

BACKGROUND: This research focused on the impacts of different dibutyl phthalate (DBP)/dioctyl phthalate (DOP) weight ratios on the surface morphology and the properties of poly (vinylidene fluoride) (PVDF) thermally induced phase separation (TIPS) microfiltration hollow fiber membranes. The phase diagrams of PVDF/DBP/DOP systems were determined and the optimum weight ratio DBP/DOP in the liquid–liquid region of the binary phase diagram was chosen to form a membrane with interconnected sponge‐like structure. Optimum processing temperature was determined based on analysis of the phase diagrams and industrial applications. In addition, the morphology and properties of the membranes were characterized as well as the performance of the membrane modules. RESULTS: Suitable processing temperature range for the PVDF TIPS process was from 430 to 493 K. A PVDF concentration of 35 wt% and weight ratio DBP/DOP of 1/2 provided the most appropriate membrane for industrial application. CONCLUSIONS: The optimum processing temperature range for the PVDF TIPS process was determined. The weight ratio DBP/DOP in PVDF/DBP/DOP systems played an important role in preparing PVDF TIPS microfiltration hollow fibers with superior properties giving membranes suitable for industrial application. © 2015 Society of Chemical Industry