Molecular dynamics simulations of water mixtures in confinements

限制条件下水混合物的分子动力学模拟

• 批准号: 203759955
• 负责人: Professorin Dr. Barbara Drossel
• 金额: --
• 依托单位: Institut für Physik Kondensierter Materie (IPKM)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/203759955?language=en
• 关键词: Molecular; dynamics; simulations; water; mixtures

Using MD simulations, we will systematically investigate the influence of the geometry, hydroaffinity, and softness of a confinement on the structure, dynamics, and phase behavior of embedded hydrogen-bonding liquids. As guest systems, we will use pure water as well as mixtures of water with alcohol, carboxylic acids, peptides, or proteins. The host systems will be varied systematically with respect to geometry, hydroaffinity, and softness. Apart from atomistic pores, we will also use smooth walls in order to confine the liquid. Compared to the first funding period, the project will now focus more on water mixtures than on pure water. Concerning pure water, we will aim at a theoretical understanding of the dynamical slowdown in the vicinity of hard walls, in particular, for neutral confinements that to not alter the structure of water. For this purpose, we will adapt promising approaches such as the random first order theory, the shoving model, and the elastically cooperative activated barrier hopping theory for the glass transition of bulk liquids. We will also look at the wetting and phase behavior of water in partially filled pores. For mixtures of water with alcohol, carboxylic acids, and peptides, we will mainly focus on the influence of geometry and hydroaffinity of the confinement on the phase behavior. We will quantify the interplay of volume and surface effects by using spatially resolved energy and entropy considerations in order to develop thermodynamic models for demixing in confinement. For water peptide and water protein mixtures we intend to investigate the dynamical coupling between the two components under the influence of confinement so as to gain insights into the function of proteins in densely packed biological environments on the basis of suitable model systems.

利用分子动力学模拟，我们将系统地研究约束的几何形状、亲水性和柔软性对嵌入氢键液体的结构、动力学和相行为的影响。作为客户系统，我们将使用纯水以及水与酒精、羧酸、多肽或蛋白质的混合物。宿主系统将在几何结构、亲水性和柔软性方面有系统地变化。除了原子孔外，我们还将使用光滑的墙壁来限制液体。与第一个资助期相比，该项目现在将更多地关注水混合物，而不是纯净水。关于纯水，我们将致力于从理论上理解硬壁附近的动态减速，特别是对于不改变水结构的中性限制。为此，我们将采用随机一阶理论、推挤模型和弹性合作激活势垒跳跃理论等有希望的方法来研究大体积液体的玻璃化转变。我们还将观察水在部分填充的毛孔中的润湿和相行为。对于水与酒精、羧酸和多肽的混合物，我们将主要关注限制的几何形状和亲水性对相行为的影响。我们将通过空间分辨能量和熵的考虑来量化体积和表面效应的相互作用，以便建立禁闭中分离的热力学模型。对于水肽和水蛋白混合物，我们打算在合适的模型体系的基础上，研究限制条件下两组分之间的动态耦合，从而深入了解密集生物环境中蛋白质的功能。