物理化学学报 >> 2011, Vol. 27 >> Issue (02): 374-378.doi: 10.3866/PKU.WHXB20110229

理论与计算化学 上一篇    下一篇

疏水高分子单链在疏水表面上吸附和扩散过程的分子动力学模拟

牟丹1, 周奕含2   

  1. 1. 枣庄学院化学化工系, 山东 枣庄 277160;
    2. 中国科学院长春应用化学研究所, 长春 130022
  • 收稿日期:2010-09-20 修回日期:2010-12-07 发布日期:2011-01-25
  • 通讯作者: 牟丹 E-mail:mudanjlu1980@yahoo.com.cn
  • 基金资助:

    山东省优秀中青年科学家科研奖励基金计划(BS2010CL048)、山东省教育厅高等学校科技计划项目(J10LA61)、枣庄市科技攻关项目(200924-2)资助项目

Molecular Dynamics Simulation of the Adsorption and Diffusion of a Single Hydrophobic Polymer Chain on a Hydrophobic Surface

MU Dan1, ZHOU Yi-Han2   

  1. 1. Department of Chemistry and Chemical Engineering, Zaozhuang University, Zaozhuang 277160, Shandong Province, P. R. China;
    2. Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
  • Received:2010-09-20 Revised:2010-12-07 Published:2011-01-25
  • Contact: MU Dan E-mail:mudanjlu1980@yahoo.com.cn
  • Supported by:

    The project was supported by the Science-Technology Foundation for Middle-Aged and Young Scientist of Shandong Province, China (BS2010CL048), Higher School Science & Technology Fund Planning Project of Shandong Province, China (J10LA61) and Zaozhuang Scientific and Technological Project, China (200924-2).

摘要:

采用分子动力学模拟方法研究不同聚合度(N)的聚乙烯(PE)单链在Si(111)表面上的吸附和扩散行为. 分别设置相对介电常数为1和78模拟无溶剂和不良溶剂环境. PE单链的平衡吸附构象均呈现为二维吸附构象, 但在这两种截然不同的环境中呈现不同的构象和动力学特征, 说明溶剂环境对于疏水高分子单链在疏水表面上的吸附和扩散起到了很大的作用. 吸附能与聚合度呈线性关系, 单位链长的平均吸附能是-0.38 kJ·mol-1. 另外, 扩散系数(D)与聚合度之间的标度关系是D~N-3/2.

关键词: 疏水高分子单链, 疏水表面, 二维吸附构象, 标度

Abstract:

The adsorption and diffusion of polyethylene (PE) with different degrees of polymerization (N) on a silicon (111) surface were studied by molecular dynamics simulations. The relative dielectric constant was selected to be 1 and 78 to mimic a vacuum and a solution environment, respectively. The chains were all present as two-dimensional (2D) adsorption conformation on the surface but different conformations and dynamic properties were found in the two absolutely different environments. This shows that the solvent plays an obvious role in the chain adsorption and diffusion processes on a hydrophobic surface. The relationship between the adsorption energy and the degree of polymerization follows a linear function and the average adsorption energy per segment is -0.38 kJ·mol-1. In addition, the diffusion coefficient (D) of these chains scales with the degree of polymerization as N-3/2.

Key words: Single hydrophobic polymer chain, Hydrophobic surface, Two-dimensional adsorption conformation, Scaling law

MSC2000: 

  • O641