N. Akther, S. Lim, V.H. Tran, S. Phuntsho, Y. Yang, T.-H. Bae, N. Ghaffour, H.K. Shon
DOI: 10.1016/j.seppur.2019.02.034, (2019)
Forward osmosis (FO), Interfacial polymerization (IP), Covalent organic frameworks (COFs), Schiff base network-1 (SNW-1), Thin-film nanocomposite (TFN) membrane
In this study, Schiff base network-1 (SNW-1) nanoparticles, which are covalent organic frameworks (COFs), were used as fillers in the polyamide (PA) active layer to elevate the performance of thin-film nanocomposite (TFN) forward osmosis (FO) membranes. The TFN membranes were prepared by interfacial polymerization (IP) of m-phenylenediamine (MPD) and trimesoyl chloride (TMC), and the SNW-1 nanoparticles were dispersed in the MPD aqueous solution at various concentrations. The secondary amine groups of SNW-1 nanoparticles reacted with the acyl chloride groups of TMC during the IP reaction to form strong covalent/amide bonds, which facilitated better interface integration of SNW-1 nanoparticles in the PA layer. Additionally, the incorporation of amine-rich SNW-1 nanoparticles into the TFN membranes improved their surface hydrophilicity, and the porous structure of SNW-1 nanoparticles offered additional channels for transport of water molecules. The TFN0.005 membrane with a SNW-1 nanoparticle loading of 0.005 wt% demonstrated a higher water flux than that of pristine TFC membrane in both AL-FS (12.0 vs. 9.3 L m−2 h−1) and AL-DS (25.2 vs. 19.4 L m−2 h−1) orientations when they were tested with deionized water and 0.5 M NaCl as feed and draw solution, respectively.