High performance thin-film composite membranes with mesh-reinforced hydrophilic sulfonated polyphenylenesulfone (sPPSU) substrates for osmotically driven processes

We have for the first time combined the strength of hydrophilic sulfonated material and thin woven open-mesh via a continuous casting process to fabricate mesh-reinforced ultrafiltration (UF) membrane substrates with desirable structure and morphology for the development of high-performance thin-film composite (TFC) osmosis membranes. A new sulfonated polyphenylenesulfone (sPPSU) polymer with super-hydrophilic nature is used as the substrate material, while a hydrophilic polyester (PET) open mesh with a small thickness of 45 mu m and an open area of 44.5% is employed as the reinforcing fabric during membrane casting. The newly developed sPPSU-TFC membranes not only exhibit a fully spongelike cross-section morphology, but also possess excellent water permeability (A= 3.4-3.7 L m(-2) h(-1) bar(-1)) and selectivity toward NaCI (B=0.10-0.23 L m(-2) h(-1)). Due to the hydrophilic nature and low membrane thickness of 53-67 mu m, the PET-woven reinforced sPPSU substrates have remarkably small structural parameters (S) of less than 300 pm. The sPPSU-TFC membranes thereby display impressive water fluxes (J(w)) of 69.3-76.5 L m(-2) h(-1) and 38.7-47.0 L m(-2) h(-1) against a deionized water feed using 2 M NaCI as the draw solution under pressure retarded osmosis (PRO) and forward osmosis (FO) modes, respectively. This performance surpasses the state-of-the-art commercially available FO membranes. The sPPSU-TFC membranes also show exciting performance for synthetic seawater (3.5 wt% NaCI) desalination and water reclamation from real municipal wastewater. The newly developed PET-woven sPPSU-TFC membranes may have great potential to become a new generation membrane for osmotically driven processes. (C) 2015 Elsevier B.V. All rights reserved.