Fabrication of asymmetric cellulose acetate/pluronic F-127 forward osmosis membrane: minimization of internal concentration polarization via control thickness and porosity

Abstract

The core of this study was fabrication of novel cellulose acetate/pluronic F-127 (CA/PF-127) composite membranes for forward osmosis (FO) applications. Performance and structure of the FO membranes under the influence of different applicator clearance gaps (ACGs) along with PF-127 wt.% contents were examined during the non-solvent phase separation (NIPS) method. Scanning electron microscopy, water contact angle, atomic force microscopy and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) analysis were used to characterize the membrane properties. The best performance was attributed to the lower thickness and the higher porosity. The lower structural parameter, which reduces the internal concentration polarization (ICP), led to the highest water flux. The values of 10.58 (L/m2.h) and 0.39 (g/L) were obtained as water flux and specific reverse salt flux (SRSF) of the optimal FO membrane, which was synthesized by 20 wt.% of CA, 79.00 wt.% of N-methyl-2-pyrrolidone (NMP), 1.0 wt.% of PF-127 and 100 µm of ACG, respectively.