Nanocellulose-based membranes for highly efficient molecular separation

Nanocellulose (NC), a family of most promising natural nanomaterials, has emerged as a potential candidate for the fabrication of highly efficient separation membranes owing to its unique one-dimensional nanostructure, hydrophilic property, easily designed surface chemistry as well as outstanding mechanical strength. In this paper, we review the latest advancements on the state-of-the-art NC-based membranes for molecular separation in water treatment, chemical industries, seawater desalination and battery fields. Based on the function of NC, NC-based membranes are classified as NC-assembled membranes, NC/2D nanomaterial composite membranes, functional NC membranes, thin-film nanocomposite membranes, and thin-film composite membranes with NC as an interlayer. Their preparation methods, physicochemical structures, separation performances and separation mechanisms are summarized to elucidate the role of NC. A summary and perspective are further provided on the opportunities and challenges in this arising field. The aspects discussed may promote green development of advanced membranes, considering the growing concerns about sustainable resource.