Cooperative Atomic Motion in the Interfacial Dynamics of Strongly Interacting Particle Systems

强相互作用粒子系统界面动力学中的原子协同运动

• 批准号: 355392-2012
• 负责人: Zhang, Hao
• 金额: $ 1.75万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=549716
• 关键词: Cooperative; Atomic; Motion; Interfacial; Dynamics

Thermally excited collective string-like particle motion is a general property of strongly interacting particle systems. It has recently become noticed that this type of cooperative motion is characteristic of the dynamics of diverse forms of glass forming liquids. Such collective atomic motion has been found in recent molecular dynamics simulations in the bulk dynamics of a wide range of glass forming liquids, and it has been directly observed in measurements on colloidal 'hard sphere' fluids. The applicant's previous molecular dynamics simulations have further indicated that string-like collective motion is prevalent in grain boundaries of polycrystalline materials and interface of nanoparticles. The recognition of the these general thermal excitations provides a general framework for understanding the sensitivity of strongly interacting particle systems to impurities, pressure and geometrical confinement and other factors that affect atomic packing and the scale of collective atomic motion. The new perspective of the origin of the special and tunable properties of strongly interacting particle systems also offers the promise of an improved rational control of their properties based on further quantification and manipulation of their interfacial chemistry and environment. The objectives of current proposal are to 1) taking nickel nanoparticles and ice-water as strongly interacting particle model systems, investigate and characterize cooperative atomic motion during sintering of nickel nanoparticles and premelting of ice, and 2) using various types of perturbations (e.g., molecular and alloy additives, hydrostatic pressure, nanoconfinement), modify the cooperative atomic motion and better understand how such collective motions influence dynamics of sintering and premelting with goals to prevent sintering and to control premelting of ice.

热激发类弦集体粒子运动是强相互作用粒子系统的一般性质。最近人们注意到，这种类型的协同运动是各种形式的玻璃形成液体的动力学特征。这种集体原子运动已经在最近的分子动力学模拟中发现，在广泛的玻璃形成液体的体动力学中，它已经在胶体“硬球”流体的测量中直接观察到。申请人先前的分子动力学模拟进一步表明，在多晶材料的晶界和纳米颗粒的界面中普遍存在弦状集体运动。对这些一般热激发的认识为理解强相互作用粒子系统对杂质、压力、几何约束和其他影响原子堆积和原子集体运动规模的因素的敏感性提供了一个总体框架。强相互作用粒子系统的特殊和可调性质的起源的新视角也提供了基于对其界面化学和环境的进一步量化和操纵来改进其性质的合理控制的希望。本课题的目标是：1)将纳米镍颗粒和冰水作为强相互作用的粒子模型系统，研究和表征纳米镍颗粒烧结和冰预熔过程中的协同原子运动；2)使用各种类型的扰动（例如，分子和合金添加剂、静水压力、纳米约束）。修改原子的协同运动，更好地了解这种集体运动如何影响烧结和预熔动力学，以防止烧结和控制冰的预熔。