Facilitating the fabrication of diverse bio-based nanomaterials from bamboo using one-pot hydrated deep eutectic solvent pretreatment

Abstract

The conversion of biomass feedstocks into bio-based nanomaterials was made easier with hydrated DES (HDES) pretreatment, which can boost the value-added applications of lignocellulosic biomass. In this study, two types of HDESs were initially prepared by 3-Chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC) with formic acid (FA) and acetic acid (AA), respectively. We achieved rapid conversion of bamboo feedstock into bio-based nanomaterials (including lignin nanoparticles, LNPs; lignin-containing cellulose nanofibers, LCNFs) through one-pot microwave-assisted HDES pretreatment coupled with robust nanofabrication strategies. The findings demonstrated that an impressive delignification ratio of 92.10 % and a cellulose retention ratio of 92.95 % were achieved under the optimal DES pretreatment conditions (120 °C, 20 min). The fractionated lignin fractions were effortlessly self-assembled into dispersed, uniformly shaped circular LNPs (<100 nm) using a novel proposed strategy, which was successfully applied to stabilizing oil-in-water (O/W) Pickering emulsions. To produce LCNFs, we conducted functionalization of cellulose-rich residue in aqueous citric acid followed by simple ultrasonic treatment. Compared to the control LCNF, the LCNF-based self-assembly films exhibited significantly improved mechanical properties and hydrophobicity (water contact angle 106.26°). In short, the proposed HDES pretreatment combined with robust nanofabrication strategies will broaden the fractionation and fabrication of bio-based nanomaterials, enhancing their potential in promising fields.