Thin-film composite forward osmosis membrane with high water flux and high pressure resistance using a thicker void-free polyketone porous support

In this study, we investigated the effect of the morphology of the support membrane on the forward osmosis (FO) flux and maximum hydraulic breaking pressure of thin-film composite (TFC) FO membranes for engineered osmosis applications. Eight types of porous support membranes were prepared using polyketone as a polymer material by changing the coagulation bath composition and initial casting height via the non-solvent induced phase separation method. The intrinsic membrane parameters of the prepared TFC FO membranes were determined from both reverse osmosis and FO experiments. The results revealed that there was a good correlation between the FO flux and the partial dense part morphology of the support layer, whereas the hydraulic breaking pressure strongly depended on the thickness of the entire support layer and the presence of large voids. This significant difference enabled the design of an optimal TFC FO membrane that exhibited both high FO flux as well as high pressure resistance. The prepared TFC FO membrane showed an FO flux of 24.8 L m^{− 2} h^{− 1} when tested in the active layer facing to feed solution mode using 0.6 M sodium chloride and deionized water as draw solution and feed solution, respectively, with a pressure resistance of 19 bar.