Interfacial Engineering of Carbene-Functionalized ZIF-90 Porous Liquid-like Dispersion-Based Mixed Matrix Membranes for Enhanced Ethanol Recovery via Pervaporation

Abstract

Mixed matrix membranes (MMMs) are promising for overcoming the permeability–selectivity limitations of polymeric membranes, yet their performance is often restricted by filler aggregation and interfacial defects at high loadings. Here, we introduce ZIF-90 in a porous liquid-like dispersion form as a filler for high-performance MMMs. Carbene functionalization provides liquid-like interfacial compatibility while preserving the microporosity of ZIF-90, enabling homogeneous nanoscale dispersion within a polydimethylsiloxane (PDMS) matrix at high loading. This architecture creates continuous selective transport pathways and suppresses nonselective interfacial defects. Consequently, the ZIF-90-PL/PDMS membrane exhibits enhanced permeability and selectivity, achieving a total flux of 3.86 kg m–2 h–1 and a separation factor of 29.3 for ethanol recovery at 60 °C with 45 wt % loading, outperforming conventional MMMs. Mechanistic analysis reveals that functionalization enhances ethanol-selective sorption and reduces diffusion resistance, mitigating the permeability–selectivity trade-off. These findings establish the porous liquid-like MOF dispersion as an emerging class of membrane fillers for future separation membranes.