Improved performance of three-component structure mixed membrane for pervaporation modified by lignosulfonates@2D-MXene

Abstract

Hydrophilic calcium lignosulfonate combined with 2D-MXene, jointly modified the polysaccharide sodium alginate to prepare a mixed matrix membrane, which has excellent alcohol-water separation performance. • Pervaporation membrane made of sodium alginate, MXene@calcium lignosulfonate. • The hydrophilicity of the membrane increases and the obvious layered structure appears. • The selectivity and permeability of ethanol dehydration are improved simultaneously. Lignosulfonates are a by-product of the agricultural and forestry waste and paper industries. Strengthening the sustainable use of lignosulfonates is a problem to be solved. In this study, hydrophilic agricultural and forestry waste calcium lignosulfonate (CaLS) was combined with single/double-layered MXene, and added to the natural polysaccharide sodium alginate (SA) to prepare a pervaporation me, membrane with a three-component hybrid structure. Characterization experiments such as scanning electron microscopy and contact angle demonstrated that CaLS increased the hydrophilicity and reduced swelling of the membrane, and MXene formed a layered cross-sectional morphology that further reduced swelling. A 90% ethanol aqueous solution was used to evaluate the dehydration performance of the membrane. The results showed that the permeation flux and separation factor of the membrane increased by 74% and 160%, respectively. Compared to the pure SA membrane after CaLS was incorporated. MXene further improved the pervaporation performance of the MXene@CaLS/SA membrane, with the permeation flux of about 938 g·m −2 ·h −1 , and the separation factor of 4612 (two and four times higher than the pure SA membrane, respectively). This study provides a theoretical and technical basis for the development of new separation materials, and will help expand the high-value utilization of lignosulfonates.