This paper explored the mechanism of dissociation of hemicellulose using lactic acid (LA)-based deep eutectic solvents (DESs) synthesized with different hydrogen bond acceptors (HBAs) via simulations. Density functional theory (DFT) calculations and molecular dynamics (MD) simulations revealed that DESs synthesized with guanidine hydrochloride (GuHCl) as hydrogen bond acceptor (HBA) demonstrated better hemicellulose solubilization compared to the conventional DESs synthesized using choline chloride (ChCl) as HBA. The best interaction with hemicellulose was achieved at GuHCl:LA = 1:1. The results showed that CL⁻ played a dominant role in the dissolution of hemicellulose by DESs. Unlike ChCl, the guanidine group in GuHCl had the delocalized π bond, which made CL⁻ have stronger coordination ability and promoted dissolution of hemicellulose by DESs. Moreover, multivariable analysis was employed to establish the correlation between the effects of different DESs on hemicellulose and the molecular simulation results. Additionally, the influence of different HBAs functional groups and carbon chain length on the solubilization of hemicellulose by DESs were analyzed.

本文通过模拟探讨了使用不同氢键受体（HBA）合成的乳酸（LA）基低共熔溶剂（DES）解离半纤维素的机制。密度泛函理论（DFT）计算和分子动力学（MD）模拟表明，与使用氯化胆碱（ChCl）作为HBA合成的传统DES相比，以盐酸胍（GuHCl）作为氢键受体（HBA）合成的DES表现出更好的半纤维素溶解能力。当 GuHCl:LA = 1:1 时，可实现与半纤维素的最佳相互作用。结果表明，CL ^-在 DES 溶解半纤维素的过程中起主导作用。与 ChCl 不同，GuHCl 中的胍基具有离域 π 键，这使得 CL ^-具有较强的配位能力，促进DESs对半纤维素的溶解。此外，采用多变量分析建立了不同DES对半纤维素的影响与分子模拟结果之间的相关性。此外，还分析了不同HBA官能团和碳链长度对DES溶解半纤维素的影响。