High-performance acid-stable polysulfonamide thin-film composite membrane prepared via spinning-assist multilayer interfacial polymerization

Acid-resistant membrane has an important application prospect in the field of industrial wastewater treatment. Polysulfonamide (PSA) filtration membrane possessing good stability in acidic condition was often hampered for application due to the poor performance by the state-of-the-art interfacial polymerization (IP) preparation method. Herein, a spinning-assist multilayer interfacial polymerization (sMIP) method was devised and employed for the fabrication of a PSA thin-film composite (TFC) membrane from piperazine (PIP) and 2,4,6-tris(chlorosulfonyl) phenol (TCSP). Membrane fabricated with 5 layers by sMIP method exhibited greater than 98% rejection rate for Na2SO4 and MgSO4 and outperformed the control IP group by ~ 147% enhanced water permeance and a magnitude greater permselectivity due to a reduced active layer thickness. Compared with polyamide membranes, the PSA TFC membrane exhibited better stability toward acid through a high-temperature treatment in a 20% H2SO4 aqueous solution. For a CuSO4 and H2SO4 mixed solution filtration, the PSA membrane exhibited good permselectivity with CuSO4 rejection of 78% and H2SO4 rejection of 8% at a permeate flux of 13.98 L m−2 h−1. These results have demonstrated that the sMIP method provides an effective way to fabricate polysulfonamide membrane with excellent salt rejection as well as appreciable water permeance.