Surface functionalization of poly(vinylidene fluoride) membrane by radiation-induced emulsion polymerization of hydroxyethyl acrylates in an aqueous medium

Abstract

Decades ago, surface modification of poly(vinylidene fluoride) (PVDF) membrane became an essential subject. The change is mainly to enhance the hydrophilicity properties of the membrane in order to increase the adsorption capacity, thus making as a novel adsorbent. This study aims to used radiation-induced polymerization and compares the final properties of PVDF grafted hydroxyethyl acrylates (HEA) prepare by two different approaches. The PVDF-grafted-HEA has achieved either direct polymerization or emulsion polymerization. Tween-20 has been used as a surfactant in emulsion polymerization. The final PVDF-grafted poly-HEA was analyzed using several different instruments to observe the changes in terms of morphological structure, topography properties, thermal stability, mechanical strength, and hydrophilicity. Significant differences were seen in morphology and contact angles properties. By emulsion polymerization, poly-HEA grafted in the shape of micelles compare to by direct polymerization shown a thin homogenous layer. Thus, the surface roughness of PVDF by emulsion is higher lead to higher contact angles. Even though both approaches demonstrate significant changes in the physicochemical properties of the PVDF membrane, it is revealed that radiation-induced direct polymerization approaches could achieve a hydrophilic PVDF-grafted HEA.