Novel TFC membrane with PMIA thin-film as active layer fabricated by the T-FLO technique for dye desalination

Abstract

Poly (m-phenylene isophthalamide) (PMIA) generally is employed in a thin-film composite (TFC) membrane as the porous substrate via the non-solvent induced phase separation technique. Relatively little research has been done on PMIA thin-films. Here, dense PMIA thin-film was deposited via the cast-coating coupled solvent evaporation and was modified systematically. The ion permeance of PMIA thin-film has been explored for the first time. Furthermore, the novel TFC membrane with PMIA active layer (TFC-P10) was successfully fabricated for the first time via the thin-film liftoff (T-FLO) technique. The mechanism of applying PMIA thin-film as the active layer was illustrated by SEM, FTIR and XPS as the secondary amine group of PMIA reacted with the epoxide group of the epoxy layer. TFC-P10 performed remarkable dye desalination. Specifically, Congo red (CR) rejection of 99.55 % (50 mg L−1), NaCl rejection of 7.34 % (1000 mg L−1), high-temperature resistance under 90 °C, good antifouling with FRR > 90 %, and 96 h long-term stability. Besides, the dye/salt selectivity coefficient α of TFC-P10 was 207.9. This work endows a guideline for in-situ dye effluent treatment and the novel TFC membrane fabrication.