Thermally stable thin-film nanocomposite nanofiltration membranes confined by MoS2 nanosheets for high temperature separation

Thermally stable polymer nanofiltration membranes are urgently demanded in high temperature separation. However, thin-film composite (TFC) nanofiltration membranes fabricated by conventional interfacial polymerization suffer from pore size expansion and thermal instability under high temperature. Herein, we report the fabrication of MoS 2 nanosheet confined thin-film nanocomposite (TFN) membranes with enhanced thermal stability. The structural stability of the nanofiltration membranes were investigated by in-situ FTIR and in-situ AFM at different temperatures. The MoS 2 nanosheets significantly improve the thermal stability of the nanofiltration membranes by stabilizing the pores and surface strength under high temperature. Molecular dynamic (MD) simulation further confirms the confinement effect of the MoS 2 nanosheets on the thermal mobility of the polyamide chains. The TFN membrane presents a prominent permeance of over 30.0 L·m −2 ·h −1 ·bar −1 and high rejections to Na 2 SO 4 (99.8 %) and MgSO 4 (98.1 %) at 80 °C. It also shows long-term stability and desirable selectivity of SO 4 2− /Cl − at 80 °C. This work provides a feasible strategy for designing thermally stable nanofiltration membranes with excellent performance.