化学学报 ›› 2007, Vol. 65 ›› Issue (20): 2249-2256. 上一篇    下一篇

研究论文

水溶性聚合物与硬石膏晶体相互作用的分子动力学模拟

张曙光*,1,王风云2,雷武2,夏明珠2   

  1. (1山东理工大学化工学院 淄博 255049)
    (2南京理工大学化学系 南京 210094)
  • 投稿日期:2006-11-13 修回日期:2007-03-08 发布日期:2007-10-28
  • 通讯作者: 张曙光

Molecular Dynamics Simulation of Interaction between Water-Soluble Polymers and Anhydrite Crystal

ZHANG Shu-Guang*,1 ;WANG Feng-Yun2 ;LEI Wu2 ;XIA Ming-Zhu2   

  1. (1 School of Chemical Engineering, Shandong University of Technology, Zibo 255049)
    (2 Department of Chemistry, Nanjing University of Science & Technology, Nanjing 210094)
  • Received:2006-11-13 Revised:2007-03-08 Published:2007-10-28
  • Contact: ZHANG Shu-Guang

用分子动力学(MD)方法, 模拟计算了6种水溶性聚合物阻垢剂{聚丙烯酸(PAA)、聚甲基丙烯酸(PMAA)、丙烯酸-丙烯酸甲酯共聚物[P(AA-co-MAE)]、丙烯酸-丙烯酸羟丙酯共聚物[P(AA-co-HPA)]、聚马来酸(HPMA)、丙烯酸-马来酸共聚物[P(AA-co-MA)]}与硬石膏晶体的相互作用. 结果发现, 聚合物与硬石膏晶体结合能的大小排序为P(AA-co-MA)>HPMA>P(AA-co-HPA)>P(AA-co-MAE)>PMAA>PAA, 同种聚合物阻垢剂对硬石膏两晶面生长的抑制能力相差不大. 对体系各种相互作用以及对关联函数g(r)的分析表明, 体系结合能主要由库仑作用提供. 与硬石膏晶体结合的聚合物发生明显形变, 但形变能远小于体系的非键作用能. 聚合物中不同位置羧基的动力学行为差别很大, 链端羧基的运动翻转比链中部羧基剧烈得多, 因后者与硬石膏晶体的结合比前者牢固而能更有效地抑制垢晶体生长.

关键词: 分子动力学, 水溶性聚合物, 硬石膏, 阻垢剂, 结合能, 对关联函数, 形变能

The interactions between six kinds of water-soluble polymers, polyacrylic acid (PAA), polymethacrylic acid (PMAA), acrylic acid-methyl acrylate copolymer [P(AA-co-MAE)], acrylic acid-2- hydroxypropyl acrylate copolymer [P(AA-co-HPA)], hydrolyzed polymaleic anhydride (HPMA) and acrylic acid-maleic acid copolymer [P(AA-co-MA)] and anhydrite crystal have been simulated by molecular dynamics (MD). The results show that the order of binding energy for the six polymers with anhydrite crystal is as follows: P(AA-co-MA)>HPMA>P(AA-co-HPA)>P(AA-co-MAE)>PMAA>PAA, and no distinct difference appears between the scale inhibition efficiencies of the same polymer against two crystal faces of the anhydrite. The analysis of various interactions and pair correlation functions of all systems indicates that binding energies are mainly determined by Coulomb interaction. The polymers were deformed during their combination with anhydrite crystal faces, but all the deformation energies were far less than the respective nonbonding energies. The dynamic behaviors of the carboxyls located in different positions of polymer chains are widely different. The carboxyls at the end of chains oscillate more rapidly than those in the middle, so the middle ones hinder the growth of scale crystal more effectively than end segments because they combine with the anhydrite crystal more firmly.

Key words: molecular dynamics, water-soluble polymer, anhydrite, scale inhibitor, binding energy, pair correlation function, deformation energy