In-Situ Growth of Zif-8/Pdms Membrane at the Liquid-Liquid Interface for Efficient Ethanol Recovery

Abstract

In this work, zeolitic imidazolate framework-8 (ZIF-8) particles were synthesized in situ within polydimethylsiloxane (PDMS) membranes via a liquid-liquid interface. The simultaneous formation of ZIF-8 particles and crosslinking of PDMS at the liquid-liquid interface led to (1) smaller ZIF-8 particle sizes (average 130 nm), (2) improved ZIF-8/PDMS compatibility and (3) a protective PDMS layer covering the ZIF-8 particles. Microscopy and spectroscopy techniques confirmed the optimal integration of in-situ grown ZIF-8 within the PDMS matrix. The resulting ZIF-8/PDMS membrane exhibited excellent pervaporation performance, achieving a high flux of 2.6 kg·m-2·h-1 and a separation factor of 13.1 for a 5 wt.% ethanol/water mixture. Importantly, the PDMS layer prevented direct contact between ZIF-8 and the feed, maintaining superior performance over 100 hours. The in-situ growth approach via liquid-liquid interface showed great potential for enhanced ethanol recovery.

Keywords: ZIF-8/PDMS, in-situ growth, liquid-liquid interface, mixed matrix membrane, pervaporation.