Production of superwetting cellulose II based membranes with excellent oil/water emulsions separation performance

Superhydrophilic textiles with underwater superoleophobicity have shown excellent separation performance for emulsified oil in wastewater, but their hierarchical structure and hydrophilic chemical design are complicated. Herein, a hydrophilic hierarchical layer of cellulose is constructed on commercial cotton fabrics surface through in-situ self dissolving and regenerating strategy. During the process, zinc chloride solution is used as solvent to dissolve cellulose, and sodium sulfate is used as pore forming agent to obtain open porous structure. The cellulose provides both hydrophilic surface and hierarchical structural foundation for the remodeled cotton fabrics (RCFs) without any further chemical modification. Based on the robust mechanical stability, superhydrophilicity, underwater superoleophobicity (θoil > 150º), and anti-oil fouling property, the RCFs achieved a remarkable separation performance for oil-in-water emulsions with high separation efficiency (> 99.0%) and recyclable antifouling performance. The developed RCFs assembly strategy provides an excellent membrane for oil-in-water emulsion separation, and a new prospect for the convenient and universal construct of other superwetting cellulose-based materials.