Lignin bonded composite nanofibers membrane with ZIF-L intercalation: Combining toughness, high flux and rejection for dyestuff wastewater purification

Cellulose nanofibers-based membranes with balanced mechanical strength, flux and rejection rate are highly demanded in the purification of contaminated water, nevertheless, which still hard to achieve. In this work, an interfacial engineering strategy was proposed to fabricate cellulose nanofibers-based composite membranes (LC/DA@ZIF x ) using aramid nanofibers (ANFs) as reinforcing agents, lignin as interfacial binder, and 2-dimensional leaf-shaped zeolitic imidazolate framework (ZIF-L) as pore modifier. Ascribing to the dense noncovalent interactions (e.g., H-bond and π-π stacking) among each components, as well as the hierarchically layered structure, the composite membranes simultaneously exhibited promising mechanical properties (a mechanical strength of ∼163 MPa and a toughness of ∼11.89 MJ/m 3 ), flux (61.95 L·m −2 ·h −1 ·bar −1 ), and rejection rates toward contaminated water (∼97.60 % for methyl violet, 98.68 % for rhodamine B, 97.12 % for rhodamine 6 G, 93.99 % for malachite green and 98.31 % for Coomassie brilliant blue). After 10 cycles of separation, the membranes can still retain a rejection rate of ∼69.98 %. Therefore, this study provided a simple and efficient strategy for manufacturing strong cellulose-based membranes that were suitable in the fast and efficient remediation of dyestuff effluent.