Conventional thin film composite (TFC) membranes have been used for various filtration applications, such as ultrafiltration, nanofiltration, and reverse osmosis. Typical structural features of these membranes are primarily based on a thin hydrophilic top-coating layer (0.2 to a few micrometers thickness) and an asymmetric porous mid-layer membrane supported by a non-woven substrate. In order to improve the permeate flux without the compromise of selectivity; thickness and permeability of each layer have to be carefully optimized. Practically, each layer- thicknesses (coating and mid-layer) are difficult to control with lowest possible values because thinner films can lead to structural disintegration. Thus, highly water permeable materials for each layer are desired to improve the permeate flux as long as they can retain the selectivity.
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