Facile fabrication of Al-fumarate mixed matrix membranes for azeotrope mixture separation

Abstract

Pervaporation has emerged as a promising technology for the separation of methanol azeotropes. However, developing membrane material to enhance the separation performance remains crucial. In this study, aluminum fumarate (Al-fu) particles were successfully incorporated into polyvinyl alcohol (PVA) via in-situ growth method, creating mixed matrix membranes (MMMs) on a porous polyacrylonitrile substrate. These Al-fu MMMs were then used for the separation of the methanol azeotropes. Compared to pure PVA membranes, the Al-fu MMMs exhibited a significant increase in both the separation factor and flux when separating a 20/80 wt% methanol/dimethyl carbonate mixture at 40 °C. The separation factor increased from 9.2 to 13.2, while the flux increased from 376.8 g·m⁻²·h⁻¹ to 928.2 g·m⁻²·h⁻¹. This enhancement can be attributed to the synergetic effects of size sieving through the pore windows and preferential adsorption of polar solvent molecules by the Al-fu MMMs. Furthermore, the low cost of both Al-fu and PVA, coupled with the facile membrane preparation process, renders this strategy economically viable and practical. Consequently, this approach offers a promising avenue for the development of efficient pervaporation membranes for the separation of azeotropic mixtures.