Hydrophobic polydimethylsiloxane thin-film composite membranes for the efficient pervaporative desalination of seawater and brines

The pervaporative desalination of synthetic seawater and brines was studied to explore the water flux salt rejection a thin-film composite (TFC) membrane made polydimethylsiloxane (PDMS) dip-coated on porous polysulfone support. Despite hydrophobic nature rubbery PDMS, we demonstrate that nonporous TFC membranes exhibit remarkable performance as evidenced by very high permeance 99.8 ± 0.2% NaCl rejection. For comparison, two commercial hydrophilic polyamide designed for reverse osmosis (RO) were also tested in pervaporation mode. At highest temperature explored (85 °C) PDMS produced an outstanding pure ∼70 kg m−2 h−1, which 2.6 times higher than best RO this work. Although presence feed reduced 36 h−1 (at brine sodium chloride concentration 70,000 ppm 85 °C), performed among compared with previously reported polymer membranes.