Mesh-Embedded Polysulfone/Sulfonated Polysulfone Supported Thin Film Composite Membranes for Forward Osmosis

In this work, mesh-embedded polysulfone (PSU)/sulfonated polysulfone (sPSU) supported thin film composite (TFC) membranes were developed for forward osmosis (FO). The robust mesh integrated in PSU/sPSU sublayer imparts impressive mechanical durability. The blending of hydrophilic sPSU in PSU sublayer affects the hydrophilicity, porosity, pore structure, and pore size of mesh-embedded PSU/sPSU substrates, and the total thickness, cross-linking degree, and roughness of the corresponding TFC-FO membrane active layers. An appropriate incorporation of sPSU not only significantly decreases the structural parameter, S of the mesh-embedded substrate to 220 μm, which is the lowest reported value for fabric backed FO membrane, but also optimizes the permselectivity of the formed active layer. Regarding the osmosis performance, TFC membranes with sPSU modified substrates gain a higher water flux (Jw) while keeping the specific reverse salt flux (Js/Jw) low. The optimal TFC-FO membrane has a Jw of 31.76 LMH with Js/Jw of 0.19 g/L in FO mode when using deionized water feed and 1 M NaCl draw solution. This paper is practical for developing TFC-FO membrane on hydrophilic support membrane materials.