Highly improved reverse osmosis performance of novel PVA/DGEBA cross-linked membranes by incorporation of Pluronic F-127 and MWCNTs for water desalination

Abstract

A novel Poly (vinyl alcohol) (PVA) reverse osmosis (RO) membrane with unique performance and characteristics was synthesized for water desalination. PVA thin film nanocomposite (TFN) membranes were fabricated by the infusion of Pluronic F-127 and multi-wall carbon nano-tubes (MWCNTs) in a single layer crosslinked by bisphenol A diglycidyl ether (DGEBA). The overall RO performance of the membranes including hydrophilicity, surface roughness, water permeability, salt rejection, chlorine resistance and biofouling resistance was evaluated using a dead end RO filtration unit. The incorporation of Pluronic F-127 and MWCNTs improved the overall RO performance of the membranes. It was found that the modified membranes surface became smoother and highly hydrophilic compared to the pristine PVA membranes surfaces. This study indicated that the membranes that contain 0.08 and 0.1wt% MWCNTs provided excellent permeation, salt rejection, Chlorine and biofouling resistance and mechanical strength. The most striking result to emerge from this study is that the overall RO performance enhancement has transpired while utilizing PVA as an active RO separation layer without a polymeric or ceramic substrate. This study shows that proper crosslinking of PVA coupled with mechanical strength enhancement overcomes the common PVA drawbacks, mainly swelling and rupture under very high pressure.