Total–Component Valorization of Lignocellulose via a Ternary Deep Eutectic Solvents

EG capping suppresses lignin condensation, yielding highly reactive lignin. • BL–ESO bio-adhesive exhibits 2.11 MPa strength and NIR self-healing properties. • LCNF boosts PVA film strength by 2.24-fold and enables UV-shielding. • Achieving total valorization of lignocellulose into functional materials. Traditional deep eutectic solvent (DES) pretreatments are often hindered by lignin condensation and solvent recycling challenges. To address these limitations, a ternary choline chloride–malic acid–ethylene glycol (ChCl–MA–EG) DES system is designed for total–component valorization of wheat straw. By integrating acidic cleavage with nucleophilic stabilization, this system selectively cleaves lignin–carbohydrate linkages while suppressing lignin condensation, enabling effective separation into a liquor fraction (lignin and hemicellulose) and solid residue (cellulose). The resulting DES black liquor can be directly copolymerized with epoxidized soybean oil to fabricate a bio–adhesive, exhibiting exceptional photothermal conversion and self–healing capabilities. Simultaneously, the cellulose–rich residue is processed into lignin–retaining cellulose nanofibers (LCNF, ∼20 nm). By incorporating 10% (mass) LCNF into a poly(vinyl alcohol) (PVA) matrix, the resulting composite film shows a boosted mechanical strength of 56.35 MPa and improved UV–blocking capability. This approach mitigates lignin condensation and solvent recovery challenges, establishing a green biorefinery process for upgrading agricultural waste into value–added functional materials. Download: Download high-res image (379KB) Download: Download full-size image