Nanocellulose-intercalated MXene NF membrane with enhanced swelling resistance for highly efficient antibiotics separation

Abstract

Two-dimensional (2D) nanomaterial-based membranes display attractive properties in molecular separation and transport, which holds their great promise for a host of applications. However, notorious swelling problem of 2D membranes result in unsatisfactory molecular/ions sieving performance, and the enhancement of structural stability for 2D membranes in aqueous solution is still challenging. Herein, we demonstrate how to efficiently stabilize the Ti3C2Tx MXene laminar architecture by the insertion of flexible and hydrophilic carboxylated cellulose nanofibers (CNFs). The importing of CNFs not only acted as a bridge to combine the adjacent 2D Ti3C2Tx sheets and enhance mechanical strength, but also assumed the role of pillar to fix the interlayer distance effectively and improve the anti-swelling properties of Ti3C2Tx membrane. Moreover, the intercalation of nanocelluloses into the interlayer of delaminated Ti3C2Tx is able to distinctly increase the interlayer spacing and create more open gaps for fast and selective molecular transport. When applied in antibiotics separative filtration process, the resultant membrane exhibits outperformed anti-swelling properties in water environment up to 76 h and simultaneously possesses satisfactorily high selectivity of antibiotics (∼99.0 % for azithromycin) with unprecedentedly high pure water permeance (∼26.0 L m−2h−1bar−1). Such 2D membranes can be easily fabricated by a facile and patternable vacuum-assisted filtration and nanocellulose induced self-assembly strategy, which holds great potential for their scalability that are applicable to many applications such as seawater desalination, industrial wastewater treatment and remediation of aquatic environment.