Computational study of the dissolution of cellulose into single chains: the role of the solvent and agitation

Abstract

We investigate the dissolution mechanism of cellulose using molecular dynamics simulations in both water and a mixture solvent consisting of water with Na$$^+$$ + , OH$$^-$$ - and urea. As a first computational study of its kind, we apply periodic external forces that mimic agitation of the suspension. Without the agitation, the bundles do not dissolve, neither in water nor solvent. In the solvent mixture the bundle swells with significant amounts of urea entering the bundle, as well as more water than in the bundles subjected to pure water. We also find that the mixture solution stabilizes cellulose sheets, while in water these immediately collapse into bundles. Under agitation the bundles dissolve more easily in the solvent mixture than in water, where sheets of cellulose remain that are bound together through hydrophobic interactions. Our findings highlight the importance of urea in the solvent, as well as the hydrophobic interactions, and are consistent with experimental results. Graphical abstract

Dissolution mechanism of cellulose in a benzyltriethylammonium/urea deep eutectic solvent (DES): DFT-quantum modeling, molecular dynamics and experimental investigation

“…Furthermore, the results obtained in this paper are in good agreement with those of previous studies investigating the insightful role of urea in cellulose dissolution. 100–102…”

“…Furthermore, the results obtained in this paper are in good agreement with those of previous studies investigating the insightful role of urea in cellulose dissolution. [100][101][102] Reduced density gradient (RDG):. Within the AIM theory, the RDG approach provides a valuable tool to distinguish between different types of weak interactions, which allows graphical visualization of the distribution of non-covalent interaction regions in real space.…”

Biomass carbon mining to develop nature-inspired materials for a circular economy

“… 179 Other advancements have also been made with the addition of external forces to the MD simulation, mimicking agitation of the mixture and providing insights into the dissolution of cellulose into individual chains. 180 MD simulations have also been used to study alternatives to petroleum-derived plastics. For example, PLA/PHB (polylactic acid/polyhydroxybutyrate) mixtures were investigated to study their miscibility and properties of polymer blends.…”

The bidirectional regulation mechanism of NMMO concentration change on cellulose dissolution and regeneration

“…The stability of cellulose molecular chains is maintained by the high-density intramolecular and intermolecular hydrogen bond networks formed between the abundant hydroxyl groups on their structural units (Hirosawa et al 2017;Zhou et al 2022), and this internal hydrogen bond network is one of the main reasons for cellulose resistance to dissolution or enzymatic hydrolysis (Bregado et al 2021;Bering et al 2022). The intramolecular and intermolecular hydrogen bond interaction networks of cellulose in the cellulose Iβ form are shown in Fig.…”