Integrally skinned nano-cellular crosslinked asymmetric thin films infused with PEO-PPO-PEO block copolymer/ZnO-NPs for desalination using sea salt

Integrally skinned asymmetric (ISA) thin films, for nanofiltration (NF), were fabricated by the infusion of PEO-PPO-PEO block copolymer (Pluronic F127) and zinc oxide nanoparticles (ZnO-NPs) in bisphenol A diglycidyl ether (DGEBA) crosslinked poly (vinyl alcohol) nanocellular structure. The thin film permeation, salt rejection and chlorine resistance performance were evaluated by using indigenously fabricated NF assembly. ISA4 (0.08 wt% ZnO-NPs/Pluronic F127 6 wt%) was considered as an optimal thin film that exhibited a much higher permeation flux (1.96m³/m²/day) and salt rejection (98.7%) compared to the single layer crosslinked thin film. The chlorine exposure tests of thin films under accelerated conditions indicated that the stability of ISA4 was enhanced effectively in chlorinated water. Thin films were characterized by ATR-FTIR, SEM, AFM, and contact angle analysis. These characterizations determine the successful interactions between polymer chains and other components, morphology, topography and wettability. It was found that the thin film surface became smoother, more hydrophilic and reduced surface roughness compared to the nanocellular crosslinked thin film. The SEM micrograph analysis showed average pore size <100 nm in ISA4 thin film without any mottled surface.