ABSTRACT
An investigation of the effect of the molecular weight of polyethylene glycol (PEG) on thin-film composite (TFC) flat sheet polysulfone membrane performance was conducted systematically, for application in forward osmosis (FO) and pressure retarded osmosis (PRO). The TFC flat sheet PSf-modified membranes were prepared via a non-solvent phase-separation technique by introducing PEGs of different molecular weights into the dope solution. The TFC flat sheet PSf-PEG membranes were characterized by SEM, FTIR and AFM. The PSf membrane modified with PEG 600 was found to have the optimum composition. Under FO mode, this modified membrane had a water permeability of 12.30 Lm-2h-1 and a power density of 2.22 Wm-2, under a pressure of 8 bar in PRO mode, using 1 M NaCl and deionized water as the draw and feed solutions, respectively. The high water permeability and good mechanical stability of the modified TFC flat sheet PSF-PEG membrane in this study suggests that this membrane has great potential in future osmotically powered generation systems.
ABSTRACT
This study focuses on the development of flat sheet thin film nanocomposite (TFN) pressure retarded osmosis (PRO) membranes for the enhancement of osmotic power generation by the incorporation of laboratory-synthesised graphene oxide (GO) into the polysulfone (PSf) polymer matrix. A series of membranes containing different weight percent of GO (0, 0.1, 0.25, 0.5 and 1.0 wt%) were fabricated via a phase inversion method with polyethylene glycol (PEG) as the pore forming agent. The results show that the TFN-0.25GO membrane has excellent water flux, salt reverse flux, high porosity and an enhanced microvoids morphology compared to the control membrane. The highest power density was achieved when TFN-0.25GO was used is 8.36 Wm-2 at pressure >15 bar. It was found that the incorporation of GO into the polymer matrix has significantly improved the intrinsic and mechanical properties of the membrane.
