化学学报 ›› 2013, Vol. 71 ›› Issue (04): 649-656.DOI: 10.6023/A13010068 上一篇    下一篇

研究论文

聚合物防污材料表面水化层的分子动力学模拟

张恒a,b, 王华a, 蔺存国b, 王利b, 苑世领a   

  1. a 山东大学化学与化工学院 济南 250100;
    b 海洋腐蚀与防护国家级重点实验室 中国船舶重工集团公司第七二五研究所 青岛 266101
  • 投稿日期:2013-01-14 发布日期:2013-03-15
  • 通讯作者: 苑世领 E-mail:shilingyuan@sdu.edu.cn
  • 基金资助:

    项目受海洋腐蚀与防护重点实验室开放基金(No. KF120404)和国家自然科学基金(No. 21173128)资助.

Molecular Dynamics Simulations of Surface Hydration Layers Near Non-fouling Polymer Membranes

Zhang Henga,b, Wang Huaa, Lin Cunguob, Wang Lib, Yuan Shilinga   

  1. a School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100;
    b Science and Technology on Marine Corrosion and Protection Laboratory, Luoyang Ship Material Research Institute (LSMRI), Qingdao 266101
  • Received:2013-01-14 Published:2013-03-15
  • Supported by:

    Project supported by the Science and Technology on Marine Corrosion and Protection Laboratory Open Research Fund (No. KF120404) and the National Natural Science Foundation of China (No. 21173128).

采用分子动力学方法研究了吸附在聚二甲基硅氧烷(PDMS)和接枝聚磺酸基甜菜碱甲基丙烯酸甲酯(pSBMA)改性后的防污材料膜水化层内的水分子的结构及其动力学性质, 从微观角度解释了聚合物膜具有防污性能的原因. 模拟发现: (1)紧靠聚合物膜形成的水化层是聚合物具有防污性能的关键因素, 该水化层是溶液中的粒子(包括蛋白质分子)与聚合物膜相接触时所要克服的最主要的物理能障; (2)相对PDMS聚合物膜而言, 双离子特性自组装膜(pSBMA)在氢键、静电力的共同作用下, 可以形成空间笼状水分子网结构对水分子具有更强的束缚作用并有效降低水分子的可运动性, 形成的稳定水化层使得pSBMA具有更强的阻碍蛋白质吸附的能力.

关键词: 聚二甲基硅氧烷, 聚磺酸基甜菜碱甲基丙烯酸甲酯, 生物污损, 防污材料, 分子动力学

The prevention of nonspecific protein adsorption was a big challenge in biomedical and marine fields. Recent studies of the mechanisms of non-fouling materials have identified a strong correlation between material surface hydration and resistance to nonspecific protein adsorption. To investigate the molecular mechanism of two typical non-fouling materials PDMS and pSBMA on molecular level, a series of molecular dynamics simulations were conducted. This work concentrated on the structure properties and dynamic behaviors of water molecules that belong to the non-fouling membranes’ surface hydration layers. Water's behavior near the membrane were analyzed in energetic, dynamics and structure aspects: PMFs (potential of mean force) between hydration layer water and polymer surfaces indicated pSBMA has more advantages on binding water molecules energetically; the analyzing of diffusion coefficients, residence time, and dipole residence time of hydration layer water showed pSBMA has slower dynamics properties which demonstrate water molecules were tightly bonded by pSBMA; the illustration of atoms density profile, hydrogen bond and their number distribution showed a rich hydrogen bond network structure around pSBMA. Based on above, following conclusions were then speculated: 1) the hydration layer near non-fouling membrane has a strong relationship with the nonspecific protein adsorption which forms a physical and energy barrier during particles in solution (including proteins) come into contact with non-fouling membranes. 2) Comparing with PDMS, pSBMA as a zwitterionic polymer can bind water molecules more strongly via both electrostatic and hydrogen bonding. And the caging effects of water network formed around pSBMA can also reduce water molecules’ mobility. All these lead to a stable hydration layer that prevents non-specific protein adsorption. Simply, pSBMA generated a more energetic advantaged, tightly bounded and structured water layer by electrostatic, hydrogen bonding and caging effect. This hydration layer prevents protein from approaching the surface, resulting in a better non-fouling surface than PDMS.

Key words: poly-dimethylsiloxane, poly-sulfobetaine methacrylate, bio-fouling, non-fouling material, molecular dynamics