Enabled cellulose nanopaper with outstanding water stability and wet strength via activated residual lignin as a reinforcement

Abstract

Due to water-sensitive hydrogen bonding, uncontrolled deformation and mechanical decay of cellulose nanopaper (CNP) caused by water remain challenging. Inspired by plant cell walls and bonding strengthening, a strategy is proposed herein to produce CNPs with outstanding water stability and wet strength by using activated residual lignin as a reinforcement. Compared with lignin-free CNPs, the saturated water absorption of residual lignin CNPs is reduced by 74%, the swelling is reduced by 94%, and the wet strength is increased by 1625%. This study demonstrates a strategy with simple, eco-friendly and cost-efficient features, which has the potential to expand the field of cellulose utilization.