Effect of cellulose nanocrystals on bacterial cellulose hydrogel for oil-water separation

Cellulose hydrogels reveal potential application for oil-water emulsion separation. However, they still suffer from lower flux, resulting from their stable hydration layers. In this work, bacterial cellulose (BC)/cellulose nanocrystals (CNC) hydrogels were prepared via the immersion method. The hydrogels also showed good superhydrophilicity/underwater-superoleophobicity. They can separate oil-in-water and water-in-oil emulsions with separation efficiency > 97.6 %. More importantly, the addition of CNC improved the crystallinity of BC hydrogels and decreased the accessibility to water molecules, which increased the water flux of hydrogels. This work provides a feasible strategy to enhance the separation flowrate for oil-water emulsions.