Development of highly permeable self-standing nanocomposite sulfonated poly ether ketone membrane using covalent organic frameworks

This study developed a new symmetric and ultrathin membrane by incorporating Schiff base network-1 (SNW-1), which are covalent organic framework (COF) nanoparticles, as fillers in the sulfonated poly ether ketone (SPEK) matrix to improve forward osmosis (FO) performance. The amine-rich and porous SNW-1 nanoparticles enhanced the surface wettability of the SPEK membranes and offered additional passages for the water molecules' transport, which assisted in the elevation of membrane water flux. The modified membrane loaded with 20 wt% SNW-1 (COF-20) exhibited the best performance with a significantly higher water flux (28.5 L m⁻² h⁻¹) and lower specific reverse solute flux (SRSF, 0.05 g L⁻¹) than that of the unmodified SPEK (COF-0) membrane (water flux of 12 L m⁻² h⁻¹ and SRSF of 0.16 g L⁻¹) when experimented with deionized water and 1 M Na₂SO₄ as feed and draw solutions, respectively. The impressive FO performances of nanocomposite SPEK membranes suggest that SNW-1 nanoparticles could be used as fillers for improving the SPEK membrane's performance in the FO application.