Effect of the different layered structural modification on the performances of the thin-film composite forward osmosis flat sheet membranes – A review

Usually, membrane performances are primarily motivated by the surface morphology. The morphological structure of the thin-film composite (TFC) membrane presents new potential applications for forward osmosis (FO) activities. In this review, the effect of different layered structural modifications on the activities of the TFC-FO flat sheet membranes was reviewed, highlighting several membranes layered frameworks along with the literature evidence. Also, we thoroughly investigated how the morphological properties including surface porosity, pore size, thickness and roughness influence the performance of FO membranes. This review paper concluded that the porosity, tortuosity, membrane thickness, surface roughness, water flux, salt rejection and reverse salt fluxes were altered by different layered structural modifications on the FO membranes. In addition, layer-by-layer (LbL) surface modified TFC-FO membranes helps to (i) prevent the direct contact of the skin and support layers, (ii) minimized the water transport resistance and increased the membrane selectivity, (iii) improved the water flux and solute rejection and (iv) reduced the structural parameter (S-value) and the internal concentration polarization (ICP).