高等学校化学学报 ›› 2018, Vol. 39 ›› Issue (4): 714-720.doi: 10.7503/cjcu20170683

• 物理化学 • 上一篇    下一篇

碱/脲水溶液体系中纤维素包合物构型及纤维素与溶剂分子间相互作用力的分子动力学模拟

刘刚1, 张恒1, 孙恒2, 朱洪霞1, 张煜函1, 朱庆增1(), 苑世领1()   

  1. 1. 山东大学化学与化工学院, 济南250199
    2. 山东化工研究院, 济南250014
  • 收稿日期:2017-10-31 出版日期:2018-04-10 发布日期:2018-03-20
  • 作者简介:联系人简介: 朱庆增, 男, 博士, 教授, 博士生导师, 主要从事高分子材料研究. E-mail:qzzhu@sdu.edu.cn;苑世领, 男, 博士, 教授, 博士生导师, 主要从事分子模拟及其应用研究. E-mail:shilingyuan@sdu.edu.cn
  • 基金资助:
    山东省自然科学基金(批准号: ZR2015BM009)、 山东省科技发展计划项目(批准号: 2014GGX102030)和山东省自主创新重大专项(批准号: 2014ZZCX01106)资助

Molecular Dynamics Simulation on the Structure of Cellulose Inclusion Complexes and Interactions Between Cellulose Chains and Solvent Molecules in Alkali/urea Aqueous Solution

LIU Gang1, ZHANG Heng1, SUN Heng2, ZHU Hongxia1, ZHANG Yuhan1, ZHU Qingzeng1,*(), YUAN Shiling2,*()   

  1. 1. School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199, China
    2. Chemical Technology Academy of Shandong Province, Jinan 250014, China
  • Received:2017-10-31 Online:2018-04-10 Published:2018-03-20
  • Contact: ZHU Qingzeng,YUAN Shiling E-mail:qzzhu@sdu.edu.cn;shilingyuan@sdu.edu.cn
  • Supported by:
    † Supported by the Natural Science Foundation of Shandong Province, China(No.ZR2015BM009), the Science and Technology Development Project of Shandong Province, China(No.2014GGX102030) and the Major Projects of Independent Innovation in Shandong Province, China(No.2014ZZCX01106)

摘要:

采用分子动力学模拟方法研究了纤维素分子在碱/脲水溶液体系中形成的包合物结构, 研究了纤维素包合物的空间构型、 氢键网格结构、 纤维素分子与溶剂分子的相互作用以及碱金属阳离子对包合物稳定性的影响. 在纤维素包合物结构中, 碱金属阳离子和OH-主要吸附在纤维素分子链羟基的附近, 与纤维素上的羟基氧直接接触形成稳定的吸附构型; 尿素分子更倾向于在纤维素糖环面结构上聚集, 可以与纤维素上的羟基氧和醚键氧相互作用形成氢键. 通过对纤维素与溶剂分子间非键相互作用的研究发现, 在纤维素羟基附近, 羟基与金属阳离子之间的相互作用能最大, 其次为与尿素分子、 氢氧根离子的相互作用, 最小的为与水分子的相互作用; 在纤维素糖环面结构上, Na+、 OH-、 尿素、 水与纤维素醚键氧的相互作用远小于与纤维素羟基的相互作用, 纤维素上的醚键氧与尿素分子相互作用能最大. 比较KOH/尿素和NaOH/尿素2种溶剂体系中碱金属阳离子与纤维素羟基形成的吸附构型的结合能, 发现Na+对纤维素分子内和分子间的氢键具有更强的破坏作用, NaOH/尿素溶剂体系中的分子与纤维素分子形成的包合物构型更稳定.

关键词: 分子动力学模拟, 纤维素包合物, 碱/脲水溶液

Abstract:

The detail structure of cellulose inclusion complexes(ICs) in alkali/urea aqueous solution was investigated using molecular dynamics simulation. The spatial structure of cellulose ICs, the hydrogen-bonding network, the interactions between cellulose chains and solvent molecules and the effect of alkali metal ions on the formation of ICs were studied. The simulation results showed that the sodium ions and hydroxide ions mostly located and formed stable absorption conformation around hydroxyl and hydroxymethyl groups of cellulose. Urea molecules preferred to occupy the faces of the hydrophobic pyranose rings and form hydrogen bonds with hydroxyl groups and the pyranose ring oxygen. The interactions between cellulose chains and solvent molecules were also simulated. Nearby the hydroxyl groups, the non-bonding interactions between solvent molecules and hydroxylic oxygen atoms of cellulose were in the order of Na+>NH2CONH2>OH->H2O. On the faces of the pyranose rings of cellulose, urea molecules exhibited the strongest interaction with hydroxylic oxygen atoms. The effects of alkali metal ions in KOH/urea and NaOH/urea aqueous solutions on the stability of ICs were also discussed. Compared with K+, Na+ could form a more stable configuration of cellulose ICs.

Key words: Molecular dynamics simulation, Cellulose inclusion complex, Alkali/urea aqueous solution

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