چكيده به لاتين
In this study, thin film composite (TFC) membranes were modified using carbon nanofibers (CNFs) for forward osmosis (FO) applications. Carboxyl functionalization of CNFs was performed to increase their surface hydrophilicity and dispersion in polysulfone (PSF) as the membrane substrate. Different concentrations of both carboxyl functionalized CNFs (f-CNFs) (0.1, 0.3, and 0.5 wt%,) and raw CNFs (0.3 wt%) were incorporated in the polymer matrix and hydrophilicity, porosity, surface roughness, tensile strength and morphology of the nanocomposite substrates were characterized. It was found that existence of the f-CNFs in the polymer matrix significantly improves the intrinsic transport properties of the membrane. The TFC-FO membranes were fabricated using trimesoyl chloride (TMC) and m-phenylenediamine (MPD) for polyamide (PA) layer formation on the substrate surface. The prepared TFC membranes were evaluated in both FO and PRO modes using DI water as feed solution (FS) and 1 M NaCl solution as draw solution (DS) for the FO performance assessment. The TFC membrane containing 0.3 wt% of the f-CNFs was achieved as the optimal membrane. The FO water flux of this membrane was almost 2 times higher than the neat TFC membrane in the both modes of operation. Water flux of 13.8 L m− 2 h− 1 and specific reverse solute flux of 0.24 g L− 1 were achieved when 1 M NaCl was used as draw solution (DS) and DI water was used as feed solution (FS) under the FO mode. Furthermore, incorporation of the f-CNFs decreased the structural parameter (S) of the TFC membranes leading to lower internal concentration polarization (ICP). From the results, it was concluded that the carboxyl functionalized CNFs (f-CNFs) is a suitable candidate for TFC-FO membranes modification to achieve high membrane performance.
