Ag+-modulated T-type zeolite membrane with improved pervaporation stability for N, N-dimethylacetamide dehydration

N, N-dimethylacetamide (DMAc) is a typical strongly polar aprotic organic solvent, and its recovery by pervaporation (PV) dehydration is important for production sustainability. However, maintaining a stable permeation flux remains challenge because of the pronounced competitive adsorption of DMAc versus water on membrane surfaces. To address this issue, hollow fiber supported T-type zeolite membrane was modified in AgNO 3 solution to tune its intrinsic pore structure and surface properties. The optimal modification conditions were determined as 0.5 M AgNO 3 concentration with an 8 h exchange time. The PV results demonstrated that the Ag  +  -modulated membrane could effectively improve the stability in DMAc dehydration. Compared to a dramatic 69% flux loss observed in the original membrane at 373 K, the flux loss of the Ag + -modulated membrane was only 7% after 30 h in dehydrating a 5 wt% water/DMAc mixture. At a lower operation temperature of 353 K, the dehydration flux remained completely stable. The improvement is attributed to the weakened competitive adsorption of DMAc molecules, achieved by reducing surface polarity after Ag + modulation. In addition, the simulated results further revealed that Ag + modulation enhanced water adsorption, thereby creating a steric hindrance for DMAc molecules near the pore entrances. These results suggested that Ag + modulation effectively improves the long-term stability of T-type zeolite membrane for DMAc dehydration, and presents a promising strategy for dehydrating the similar solvents.