Computational Studies of Defect-Mediated Phenomena in Nanomaterials

该研究计划的重点是揭示纳米材料行为的基本机制，并通过计算建模使纳米材料的目标工程应用于各种工业应用。纳米材料已经吸引了巨大的、不断增长的研究兴趣，因为它们表现出许多与宏观材料根本不同的迷人特性。阻碍这些特性在现代技术中充分利用的一个核心挑战是，它们非常容易受到纳米材料缺陷的影响。在这个特别的发现基金中，目标是检查缺陷的原子起源，并阐明它们在纳米材料的结构-性能关系中的作用。为了实现这一目标，将采用多尺度计算框架。多尺度框架涉及使用不同方法的模拟，包括分子动力学、密度泛函数理论、离散位错和动力学蒙特卡罗，以捕获不同尺度的物理过程，从而全面了解纳米材料中缺陷介导的现象。这些模拟将进一步通过基于微观力学的建模来评估和开发预测本构定律。目前的研究有望提供丰富多样的仿真工具和理论模型，可广泛应用于提供精确控制和操纵纳米材料缺陷的通用工程策略。

The focus of the proposed research program is to reveal the fundamental mechanisms underlying behaviors of nanomaterials and enable targeted engineering of nanomaterials for various industrial applications, through computational modeling. Nanomaterials have attracted enormous, and growing, research interests because they exhibit many fascinating properties that are fundamentally different from their macroscopic counterparts. One core challenge preventing the full utilization of these properties in the modern technology is that they are very susceptible to defects in nanomaterials. In this particular Discovery Grant the goal is to examine the atomistic origin of defects, and clarify their role in structure-property relationships of nanomaterials. To meet this goal, a multi-scale computational framework will be employed. The multi-scale framework involves simulations using different methodologies, including molecular dynamics, density functional theory, discrete dislocation and kinetics Monte Carlo, to capture physical processes at different scales so as to bestow a comprehensive picture of defect-mediated phenomena in nanomaterials. These simulations will be further augmented by micromechanics based modeling to evaluate and develop predictive constitutive laws. The current research is expected to deliver a rich variety of simulation tools and theoretical models, which can be widely applied to provide generic engineering strategies towards precise control and manipulation of defects in nanomaterials.