Molecular dynamics of dissolution of a 36-chain cellulose Iβ microfibril at different temperatures above the critical pressure of water

• Published in: Journal of molecular liquids 2021-08, Vol.336, p.116271, Article 116271
• Main Authors: Bregado, Jurgen Lange, Tavares, Frederico Wanderley, Secchi, Argimiro Resende, Segtovich, Iuri Soter Viana
• Format: Article
• Language: English
• Subjects: Cellulose Iβ; Crystallinity; Molecular dynamics; Radial distribution function; Supercritical conditions of water; Thermodynamic calculations
• ISSN: 0167-7322
• DOI: 10.1016/j.molliq.2021.116271

[Display omitted] •First study of heating dynamics of 36-chain cellulose Iβ with water up to supercritical water regime.•Validation of CHARMM36 force field to calculate mixing enthalpy is performed.•Molecular dynamics is used to estimate solubility thermodynamic parameters.•Structural calculations allowed understanding the dissolution mechanism of cellulose.•This study corroborates experimental results of cellulose dissolution in reactors. The cellulose dissolution is an essential pretreatment process for the chemical conversion of lignocellulosic biomass into biofuels. Here, the dissolution of a 36-chain Iβ cellulose model with a hexagonal cross-section (M36HCS) in water is analyzed by Molecular Dynamics (MD) with CHARMM36/TIP3P (C36/TIP3P) force field using gradual heating at 25 MPa. Our simulations showed that the dissolution of M36HCS starts to occur between 560 K and 600 K, which agrees with experimental observations. In our system, conditions near the critical point of water reveal that translational and rotational entropies decrease, while the low hydration level increases vibrational entropy. This investigation theoretically shows that C36/TIP3P adequately reproduces the dissolution of M36HCS even in high-pressure water as corroborated in reactors.