金属纳米粒子在咪唑类离子液体中稳定性机制的多尺度模拟研究

项目名称： 金属纳米粒子在咪唑类离子液体中稳定性机制的多尺度模拟研究

项目编号： No.21463011

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 杨振

作者单位： 江西师范大学

项目金额： 50万元

中文摘要： 最近，咪唑类离子液体因其在金属纳米粒子的可控制备领域呈现出巨大的应用前景而受到广泛的关注。然而，目前对于金属纳米粒子在离子液体中稳定性机制的认知却很缺乏。为此，本项目提出基于量子化学计算和实验表征结果，构建全原子力场和粗粒化模型用于描述咪唑类离子液体的结构和动力学性质。基于所构建的势能模型，采用分子动力学模拟方法从纳米和微米两个尺度下研究离子液体在金属纳米粒子表面溶剂化层中的结构和动力学性质，以及纳米粒子在离子液体中分散/聚集的动态过程。同时，采用分块自由能微扰方法和伞型取样技术研究金属纳米粒子在离子液体中的溶剂化自由能和相互作用自由能。项目的实施有助于在分子水平建立离子液体的微结构和体系稳定性之间的构效关系，揭示金属纳米粒子在离子液体中的稳定性机制，为设计合成新型的离子液体用于可控制备金属纳米粒子提供理论指导。

中文关键词： 分子动力学模拟；自由能计算；离子液体；金属纳米粒子；溶剂化效应

英文摘要： Recently, the imidazolium-based ionic liquids have attracted considerable attention due to their potential applications for the controllable preparation of metal nanoparticles. However, the relevant knowledge of stabilization mechanism of metal nanoparticles in ionic liquids is rather lacking up to now. To this end, both all-atom force fields and coarse-grained models are developed from quantum chemistry calculations and experimental characterization data in this work, which can be used to describe the structure and dynamics properties of imidazolium-based ionic liquids. On the basis of the developed potential models, both nanometer- and micrometer-scale molecular dynamics simulations are employed to investigate the structure and dynamics properties of ionic liquids in the solvation layers around the metal nanoparticles, and the dynamical dispersion/agglomeration processes of metal nanoparticles in ionic liquids. Meanwhile, the fragment-based free energy perturbation and umbrella-sampling approaches are used to calculate the solvation and interaction (i.e. potential of mean force) free energies of metal nanoparticles in ionic liquids. The work will be helpful to set up the relationships between ionic liquid microstructures and stabilization abilities at a molecular level, and reveal the stabilization mechanism of metal nanoparticles in ionic liquids. Our work will provide a theoretical guide in the design and synthesis of novel ionic liquids for the controllable preparation of metal nanoparticles.

英文关键词： Molecular Dynamics Simulation;Free Energy Calculation;Ionic Liquid;Metal Nanoparticle;Solvation Effect