基于低共熔溶剂体系的竹纳米木质纤维素制备及性能研究  

The preparation and properties of bamboo lignocellulosic nanofibers based on deep eutectic solvent system

作　　者：苗国华 葛芳含 陈胜[1] 许凤[1] Guohua Miao;Fanghan Ge;Sheng Chen;Feng Xu(State Key Laboratory of Efficient Production of Forest Resources/Beijing Key Laboratory of Lignocellulosic Chemistry,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]林木资源高效生产全国重点实验室,生物质化学北京市重点实验室,北京林业大学,北京100083

出　　处：《中国科学:化学》2025年第1期267-276,共10页SCIENTIA SINICA Chimica

基　　金：国家重点研发计划(编号:2023YFD2201903);国家自然科学基金面上项目(编号:22178028);111(编号:B21022)资助项目。

摘　　要：本研究通过构建四种基于乳酸(lactic acid,LA)的低共熔溶剂(deep eutectic solvents,DES)体系(DES1:2-巯基丙酸/LA;DES2:3-巯基丙酸/LA;DES3:L-丙氨酸/LA;DES4:L-半胱氨酸/LA),系统研究了DES中官能团类型(-OH、-NH_(2)和-SH)及其位阻效应对毛竹预处理的影响以及纳米木质纤维素(lignocellulosic nanofibers,LCNF)制备的机理.结果表明,含有-SH官能团的DES1、DES2和DES4体系在预处理中表现出更优异的解构能力,显著提高了木质素和半纤维素去除率,并有效保留了纤维素.其中,DES4体系由于L-半胱氨酸中-NH_(2)和-SH官能团的协同作用,预处理效果最佳,LCNF得率最高,热稳定性最优,且LCNF悬浮液展现出良好的分散性和稳定性.相比之下,DES3体系由于-NH_(2)官能团的碱性特性降低了体系酸度,预处理能力较弱,LCNF得率低、性能较差.此外,通过分子动力学模拟揭示了DES体系的氢键性能(包括氢键数量、键角和键长)和纤维素与预处理体系间的相互作用能以及扩散系数之间的微观作用机制,进一步解释了不同DES体系预处理效果的差异.In this study,by designing four lactic acid(LA)-based DES systems(DES1:2-mercaptopropionic acid/LA;DES2:3-mercaptopropionic acid/LA;DES3:L-alanine/LA;and DES4:L-cysteine/LA),a systematic study was carried out to investigate the mechanisms of the types of groups(-OH,-NH_(2),and-SH)and their steric effects on the pretreatment and preparation of lignocellulosic nanofibers(LCNF).The DES1,DES2,and DES4 systems,containing-SH groups,exhibited excellent separation ability during the pretreatment process,significantly enhancing the removal of lignin and hemicellulose while effectively retaining cellulose.Notably,the DES4 system demonstrated the best pretreatment effect due to the synergistic effect of the-NH_(2) and-SH groups in L-cysteine,resulting in the highest LCNF yield,the best thermal stability,and good dispersion and stability of the LCNF.In contrast,the DES3 system showed an inferior pretreatment effect,lower LCNF yield,and performance,due to the alkaline property of the-NH_(2) group that reduced the acidity of the system.Additionally,molecular dynamics simulations revealed the microscopic mechanism of interaction between hydrogen bonding properties(including the number of hydrogen bonds,bond angles,and bond lengths)and the interaction energies between the fibers and the pretreatment system,as well as the diffusion coefficients of the cellulose into DES systems.

关 键 词：低共熔溶剂 毛竹 预处理 纳米木质纤维素 乳酸 

分 类 号：TQ352.79[化学工程] TB383.1[一般工业技术—材料科学与工程]