Fabrication of cellulose-based composite membranes for organic solvent nanofiltration

Abstract

In this paper, the methods for obtaining delamination-resistant composite cellulose membranes were considered. Different approaches to improve the adhesion of the cellulose layer to the polyester non-woven support were analyzed. The first approach, consisting in etching the PET support with solutions of trichloroisocyanuric acid in acetone, had a negative effect on the formed membranes. The negative effect was to increase the hydrophobicity of the support, resulting in peeling off of the cellulose layer. Suppression of delamination was achieved by reduction of cellulose shrinkage: by its plasticization with glycerol or sequential treatment by liquids with gradually decrease of their affinity to cellulose. Nevertheless, treatment of the membrane with an aqueous solution of glycerol resulted in a decrease of the dye rejection. The optimal technique is sequential post-processing of composite membranes with ethanol and hexane, which makes it possible to obtain strong composite cellulose membranes with high values of the rejection of the nanosized anionic dye.