Modification of graphene oxide by ATRP: A pH-responsive additive in membrane for separation of salts, dyes and heavy metals

Abstract

Incorporation of hydrophilic multifunctional compounds in to the polymeric membrane’s matrix is one of the useful methods for modification of mixed matrix membranes. Therefore, in this study, preparation and properties of polyethersulfone (PES) mixed matrix membranes with hydrolyzed polymethylmethacrylate (PMMAhyd) grafted on graphene oxide (GO-PMMAhyd) is investigated as an effective additive to improve permeability and antifouling properties. In this respect, grafting of PMMAhyd on the GO surface is done by atom transfer radical polymerization (ATRP) technique and confirm by FTIR, H NMR, EDAX and thermogravimetric analysis (TGA). During membrane formation, the membrane surface porosity improves and the hydrophilic GO-PMMAhyd nanoparticles tend to migrate toward the membrane top surfaces which confirms by FE-SEM cross-section images. Moreover, contact angle measurements show that the surface hydrophilicity enhanced after introducing GO-PMMAhyd. More importantly, prepared nanocomposite membranes show excellent performance in the separation of salts, dyes and heavy metal ions. Furthermore, it can be expected that by creating acid groups on graphene oxide plates, prepared mixed matrix membranes were pH-sensitive, so this claim is examined and proved in membranes.