Enhanced n‐butanol permselective vapor permeation by incorporating ZIF‐8 into a polydimethylsiloxane composite membrane: Effect of filler loading contents

Abstract

Fabricating high-performance mixed matrix composite membranes (MMMs) based on the integration of metal-organic frameworks (MOFs) and hydrophobic polymer matrix are highly sought for the industrial development of vapor permeation (VP) technology. In this work, ZIF-8@polydimethylsiloxane/polyvinylidene fluoride (ZIF-8@PDMS/PVDF) MMMs with various ZIF-8 nanofiller loading contents were prepared via a simple "prime" blending method. The dispersion and agglomeration of ZIF-8 nanoparticles on both surface and cross-section of these membranes were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), respectively. The hydrophobicity of as-obtained MMMs was investigated by water contact angle and swelling degree tests. Furthermore, VP experiments were carried out to evaluate the perm-selection performance of the ZIF-8@PDMS/PVDF MMMs for the butanol/water mixture separation. Compared to the conventional PDMS membrane, the separation factor and total flux of MMM with ZIF-8 loading content of 20 wt% increased by 70 % and 23 %, respectively. The mechanism of mass transfer of butanol and water molecules inside the MMMs was also discussed.