甘油水溶液氢键特性的分子动力学模拟

为了研究低温保护剂溶液的结构和物理化学特性, 以甘油为保护剂, 采用分子动力学方法, 对不同浓度的甘油和水的二元体系进行了模拟. 得到了不同浓度的甘油水溶液在2 ns内的分子动力学运动轨迹, 通过对后1 ns内运动轨迹的分析, 得到了各个原子对的径向分布函数和甘油分子的构型分布. 根据氢键的图形定义, 分析了氢键的结构和动力学特性. 计算了不同浓度下体系中平均每个原子(O和H)和分子(甘油和水)参与氢键个数的百分比分布及其平均值. 同时还计算了所有氢键、水分子之间的氢键以及甘油与水分子之间的氢键的生存周期.

Molecular Dynamics Simulation of Hydrogen Bonding Characteristics in Aqueous Glycerol Solutions

To study the structure and physicochemical characteristics of cryoprotective agent (CPA) solutions, glycerol has been chosen as a CPA and the molecular dynamics method was used to simulate glycerol and water binary systems with different concentrations. Molecular dynamics trajectories of aqueous glycerol solutions within 2 ns were obtained. After a detailed analysis of trajectories within the last 1 ns, the intermolecular radial distribution functions for C-C, C-O, C-H, O-H, O-O and H-H pairs and the backbone conformation distributions of glycerol molecules were calculated. Based on geometrical criteria, structural and dynamics characteristics of the hydrogen bonding network were analyzed. Distribution percentages and average values of the number of hydrogen bonds per atom(Oand Hatoms) and per molecule (glycerol and water molecules) were calculated. The lifetimes of total hydrogen bonds, hydrogen bonds between water molecules and hydrogen bonds between glycerol and water molecules were also studied.