化工学报 ›› 2025, Vol. 76 ›› Issue (9): 4449-4461.DOI: 10.11949/0438-1157.20250383

• 专栏:过程模拟与仿真 • 上一篇    下一篇

组分配比影响氯化胆碱-乳酸低共熔溶剂碱木质素溶解度的底层机理研究

胡国祥1(), 朱忆魁2, 龙华1, 刘晓雯1(), 熊勤钢1()   

  1. 1.华南理工大学轻工科学与工程学院,广东 广州 510641
    2.杭州纸友科技有限公司,浙江 杭州 310000
  • 收稿日期:2025-04-14 修回日期:2025-06-30 出版日期:2025-09-25 发布日期:2025-10-23
  • 通讯作者: 刘晓雯,熊勤钢
  • 作者简介:胡国祥(2000—),男,硕士研究生,872234256@qq.com
  • 基金资助:
    广州市基础与应用基础研究项目(2023A04J0672)

Study on the underlying mechanism of choline chloride-lactic acid molar ratio influencing alkali lignin solubility in choline chloride-lactic acid deep eutectic solvents

Guoxiang HU1(), Yikui ZHU2, Hua LONG1, Xiaowen LIU1(), Qingang XIONG1()   

  1. 1.School of Light Industry and Engineering, South China University of Technology, Guangzhou 510641, Guangdong, China
    2.Hangzhou Zhiyou Technology Co. ,Ltd. , Hangzhou 310000, Zhejiang, China
  • Received:2025-04-14 Revised:2025-06-30 Online:2025-09-25 Published:2025-10-23
  • Contact: Xiaowen LIU, Qingang XIONG

摘要:

本文针对氯化胆碱-乳酸低共熔溶剂(ChCl-LA)的碱木质素溶解度随乳酸摩尔比增大而提升的实验现象,从原子、分子尺度探究ChCl-LA组分配比影响碱木质素溶解度的本质机理。基于密度泛函理论,考察了不同组分配比ChCl-LA的分子表面静电势、组分间的相互作用、氢键键能,分析了这些因素与ChCl-LA溶解木质素能力的内在关系。利用分子动力学模拟,研究了不同组分配比ChCl-LA、纯乳酸与木质素的相互作用,统计分析了各组分与木质素之间的氢键数、相互作用能、径向分布函数、空间分布函数对木质素溶解的影响规律。结果表明,ChCl-LA的组分配比决定了ChCl-LA内的活性质子和氢键性质,进而影响了ChCl-LA与木质素形成氢键、催化木质素解聚的能力,从而改变了ChCl-LA的木质素溶解度。以上结果为调控ChCl-LA溶解木质素的能力提供了理论支撑,对于ChCl-LA的制备和应用以及绿色、高效溶解木质素具有重要意义。

关键词: 低共熔溶剂, 木质素, 溶解性, 计算化学, 分子模拟

Abstract:

For the increase alkali lignin solubility in choline chloride-lactic acid deep eutectic solvents (ChCl-LA) observed in the experiment when increasing the molar ratio of lactic acid, the intrinsic mechanism of the choline chloride-lactic acid molar ratio affecting the dissolution of alkali lignin in ChCl-LA was studied at atomic and molecular scales. Based on density functional theory, the electrostatic potential distribution of ChCl-LA, interaction and H-bond energy between choline chloride and lactic acid for different molar ratios of lactic acid were examined, and relationships between these factors and the capacity of ChCl-LA to dissolve alkali lignin were discussed. Using molecular dynamics simulations, interactions of lignin with lactic acid solvent and ChCl-LA with different molar ratios of lactic acid were investigated. The number of H-bonds, interaction energy, radial distribution function and spatial distribution function between each component of different ChCl-LA and LA solvent were calculated, and their effects on the process of lignin dissolution were analyzed. It was revealed that the choline chloride-lactic acid molar ratio affects the ability of ChCl-LA to form H-bonds with lignin and to catalyze the lignin depolymerization via the nature of active protons and H-bonds in ChCl-LA, resulting in its influence on the alkali lignin solubility in ChCl-LA. The above results provide theoretical support for regulating the ability of ChCl-LA to dissolve lignin, which is of great significance for the preparation and application of ChCl-LA and the green and efficient dissolution of lignin.

Key words: deep eutectic solvent, lignin, solubility, computational chemistry, molecular simulation

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