Cotton-derived green sustainable membrane with tailored wettability interface: Synergy of lignin and ethyl cellulose

Abstract

Utilizing renewable biomass components to design oil-water separation membranes is the hot spot of environmental remediation owing to their degradable and sustainable features and the increasing concern of large production of oily wastewater. Herein, the aminated lignin (AL) with multi-active sites to be constructed was loaded onto cotton fibers and then cross-linked with green ethyl cellulose (EC) to synthetize hydrophobic/lipophilic ethyl cellulose cotton (AL@Cotton-EC). Considering that methyltrimethoxysilane (MTMS) can build low surface energy coatings, we further introduced and built the superhydrophobic AL@Cotton-EC/MTMS separation membranes. The EC can wrap on the surface of cotton and assemble an interpenetrated porous structure with excellent wetting properties. Combined with the low surface energy and superwettability of MTMS, the prepared AL@Cotton-EC/MTMS exhibited an excellent separation efficiency of 99.33% in oil-water separation with good cycling stability. In addition, by simulating outdoor acidic, alkaline and salt environments, it was found that AL@Cotton-EC/MTMS still met the superhydrophobic conditions. Thus, our materials showed huge potential for treating oily wastewater. This work completed the research on the properties of oil-water separation materials. It provided new directions for the design and development of innovative materials for green, recyclable, biodegradable and alternative energy sources.