Production of dehydrated lignin-blending carboxylated nanocellulose with superior redispersion behavior and reinforcement effect for PVA nanocomposite films

This study aims to explore the redispersibility of dehydrated nanocellulose with p-toluenesulfonic acid (p-TsOH) fractionated lignin as an eco-friendly and cost-effective capping agent, to cope with the challenge of irreversible agglomeration and thus loss of nanoscale of nanocellulose upon dehydration. The intermixing of nanocellulose and p-TsOH fractionated lignin was achieved using an aqueous ethanol solution as the medium and films of lignin-blending cellulose nanofibers (L + CNF) with excellent redispersing properties were obtained after facile air-drying. With 0.02 % ammonia as the dispersing solution, the dehydrated L + CNF film was able to achieve nearly 100 % redispersion yield after 30 min of mechanical agitation. If necessary, lignin in redispersed L + CNF can be removed by simple ethanol washing and centrifugation. In addition, redispersed L + CNF can be hybridized with poly(vinyl alcohol) (PVA) in a simple process to prepare PVA nanocomposite films with excellent hydrophobic, thermally stable, antibacterial, and mechanical properties. This study provided a sustainable and cost-effective solution to the dehydration/redispersion challenges of nanocellulose.