Deconstruction of Hemp Stalks by Hydrated Deep Eutectic Solvents for Lignocellulosic Nanofibrils Preparation

Abstract

Abstract The compact hemicellulose and lignin network in hemp stalks restricts fiber nanofibrillation and dispersion stability. Herein, a molecular simulation-guided hydrated deep eutectic solvent (H-DES) strategy was developed for biomass deconstruction and lignocellulosic nanofibrils (LCNFs) production. Four acid-based H-DES systems containing choline chloride, organic acids, and water (1:2:4 molar ratio) were screened using electrostatic potential analysis, frontier molecular orbital calculations, and molecular dynamics simulations to evaluate their interactions with hemicellulose and lignin. The oxalic acid-based H-DES exhibited optimal deconstruction performance, removing 81.9% hemicellulose and 53.8% lignin while retaining cellulose I crystallinity. Subsequent ball milling produced well-dispersed LCNFs with an average diameter of 37.5 nm and a zeta potential of −29.8 mV. This work establishes a molecular-level strategy linking H-DES interactions with biomass deconstruction and nanofibrillation, enabling stable LCNFs dispersions through hemicellulose removal and partial lignin retention.