Spray-assisted assembly of thin-film composite membranes in one process

Abstract

Spray coating has been exploited to fabricate and tailor the morphologies of various components in thin film composite membranes separately. For the first time, here we exploit this technology to construct and assemble both the selective layer and porous support of a thin-film composite membrane in a single process. In our approach, spray-assisted non-solvent induced phase inversion and interfacial polymerization reduced the time required to fabricate thin-film composite membranes from 3 – 4 days to 1 day and 40 ​min. Our approach did not sacrifice membrane separation performances during desalination of a mixture comprising 2000 ​ppm of NaCl in water at 4 ​bar and room temperature. At these conditions, compared to traditional thin film composite membranes, the water permeance of our spray coated membranes was higher by 35.7 %, reaching 2.32 ​L ​m⁻² ​h⁻¹ bar⁻¹, while achieving a NaCl rejection rate of 94.7 %. This demonstrated the feasibility of fabricating thin film composites via spray coating in a single process, potentially reducing fabrication time during scale-up production.