Robust Tunicate Cellulose Nanocrystal/Palygorskite Nanorod Membranes for Multifunctional Oil/Water Emulsion Separation

Nanoporous membranes with superhydrophilic and underwater superoleophobic surfaces have shown excellent performance in oil/water emulsion separation due to their low oil adhesion and good oil/water selectivity. However, fabrication of membranes from low cost raw materials through green and sustainable routes for multifunctional separation of oily water still remains a challenge. Herein, we reported a facile strategy to prepare robust membranes from renewable tunicate cellulose nanocrystals (TCNCs) and low-cost palygorskite (PGS) for multifunctional oil/water emulsion separation. The TCNC/PGS membranes possess nanoporous structure with tunable thickness, and superhydrophilic and underwater superoleophobic surface, which could effectively separate micro/nanoemulsions with high water flux and oil rejection. Moreover, the resulting membranes exhibited high mechanical strength, excellent recyclability, and good stability under harsh conditions. More importantly, TCNC/PGS membranes could remove water-soluble contaminants (dye or heavy ions) during the oil/water separation process, leading to multifunctional water purification. Our work provided a fast and economical strategy for the fabrication of robust membranes from inexpensive and renewable nanomaterials, which would be suitable for demanding multifunctional oil/water separation.