Atomistic Simulations of Acoustic Activation of Surface Processes

表面过程声激活的原子模拟

• 批准号: 1562929
• 负责人: Leonid Zhigilei
• 金额: $ 31.06万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1562929&HistoricalAwards=false
• 关键词: Atomistic; Simulations; Acoustic; Activation; Surface

This award supports computational research into the fundamental mechanisms of the energy transfer from strong acoustic waves to the atomic-scale surface features. Surface acoustic waves are elastic waves that propagate along the surfaces of solid materials. Their ability to transfer energy long distances with little losses are actively used in many practical applications, ranging from nondestructive evaluation of mechanical properties to micro-scale manipulation of fluid flow in microfluidics devices. The ability of surface acoustic waves to influence atomic-level surfaces processes, however, remains largely unexplored. The results of this research will facilitate the development of new applications in the areas of chemical catalysis, low temperature thin film growth, and mass spectrometry of heat sensitive molecules. At a more general level, the results of this study may open up an exciting range of opportunities for using the acoustic waves as an alternative source of energy for non-thermal activation of surface processes under conditions where the temperature increase must be avoided. The involvement of students into all aspects of high-performance parallel computing and close interaction with experimental and computational collaborators will create a fertile educational environment in the quickly expanding area of scientific computing.The goal of revealing the mechanisms responsible for the acoustic activation of surface processes will be achieved through the development of advanced computational methodology for atomistic modeling of free nonlinear propagation and dissipation of strong surface and bulk acoustic waves, as well as their interaction with surface structures and adsorbates. The new computational methods will be applied for a systematic investigation of frequency up-conversion, nonlinear sharpening of the wave profiles, shock formation and the onset of rapid dissipation of acoustic waves, acoustic energy coupling to surfaces adsorbates, sub-surface crystal defects, and nanoscale heterogeneities. The conditions leading to the diffusion enhancement, desorption, or atomic-level structural rearrangements in the surface region of the substrate will be elucidated in the simulations and the domains of applicability of the acoustically-assisted surface processing will be established for several material systems of practical interest.

该奖项支持对从强声波到原子尺度表面特征的能量转移的基本机制的计算研究。表面声波是沿固体材料表面传播的弹性波。它们以很少的损失长距离传输能量的能力被积极地应用于许多实际应用中，从机械性能的无损评估到微流体装置中流体流动的微观操纵。然而，表面声波影响原子级表面过程的能力在很大程度上仍未得到探索。这项研究的结果将促进化学催化、低温薄膜生长和热敏分子质谱等领域新应用的开发。在更一般的层面上，这项研究的结果可能会开辟一系列令人兴奋的机会，在必须避免温度升高的条件下，使用声波作为表面过程非热激活的替代能源。学生参与高性能并行计算的各个方面以及与实验和计算合作者的密切互动，将为快速扩展的科学计算领域创造一个肥沃的教育环境。揭示表面过程声学激活机制的目标将通过开发先进的计算方法来实现，该方法用于对强表面和体声波的自由非线性传播和耗散及其与表面结构和吸附物的相互作用进行原子建模。新的计算方法将用于系统研究频率上转换、波剖面的非线性锐化、冲击形成和声波快速耗散的开始、声能与表面吸附物的耦合、次表面晶体缺陷和纳米级的异质性。导致基材表面区域扩散增强、解吸或原子级结构重排的条件将在模拟中阐明，并且声学辅助表面处理的适用范围将为几种实际的材料系统建立。兴趣。