CAREER: Systematic Understanding and Control of the Mechanical Properties of Functionalized Nanoporous Metals

这项学院早期职业发展(Career)计划拨款的目标是揭示控制层次化结构的纳米孔材料机械性能的物理机制，在这些结构中，支柱和接头是复杂的。纳米多孔金属可以被认为是由典型尺寸在10-100 nm范围内的支柱和关节组成的三维相互连接的网络。这些材料具有高的比表面积比、导电性、催化活性和强度。它们在许多应用中显示出巨大的前景，例如用作燃料电池和电池的高性能催化剂或电极。设计具有增强机械性能的纳米多孔金属的能力对所有应用都至关重要，但对其内部结构如何影响宏观性能仍缺乏基本的了解，特别是对于支柱和接头本身复杂的分层结构(例如，是纳米晶体)。该项目旨在揭示控制这类结构的机械性能的物理机制。这将通过利用不同尺度的现场变形实验进行全面的实验活动来实现。纳米多孔金属几何结构的影响将借助于分析和数值模型，以及通过对放大结构进行实验来研究。该项目将对分级纳米多孔金属的力学性能的变形机制产生重要的见解，从而为控制和优化其性能提供必要的基本科学知识，并使这类材料更加广泛地适应。研究活动与教育和外展工作紧密结合：研究生和本科生都将参与该项目，从而获得纳米技术和科学方面的尖端技能和专业知识；国际和平研究所将通过佐治亚州实习生教师奖学金计划和佐治亚理工学院的女性工程夏令营与亚特兰大地区的高中教师和学生合作；一些成果将作为案例研究引入佐治亚理工学院的工程课程；国际和平研究所将参与激励学生选择教师职业的技术到教学计划。

The objective of this Faculty Early Career Development (CAREER) Program grant is to uncover physical mechanisms governing the mechanical properties of nanoporous materials for hierarchical structures where struts and joints are complex. Nanoporous metals can be thought of as a three-dimensional interconnected network of struts and joints with typical size in the range 10-100 nm. These materials possess high surface-to-volume ratios, electrical conductivity, catalytic activity, and strength. They have shown great promise in many applications, for example as high-performance catalysts or electrodes for fuel cells and batteries. The ability to design nanoporous metals with enhanced mechanical properties is crucial for all applications, yet fundamental understanding of how their internal structure influences macroscopic properties is still lacking, especially for hierarchical structures where struts and joints are themselves complex (e.g. are nanocrystalline). This project aims to uncover physical mechanisms governing the mechanical properties of such structures. This will be achieved through a comprehensive experimental campaign utilizing in-situ deformation experiments across different scales. The effects of the nanoporous metal geometrical structure will be investigated with the aid of analytical and numerical models, as well as by conducting experiments on scaled-up structures.The project will generate crucial insights into the deformation mechanisms governing mechanical properties of hierarchical nanoporous metals, thus providing a basic scientific knowledge necessary for controlling and optimizing their properties and bringing closer wider adaptation of this class of materials. Research activities are closely integrated with education and outreach efforts: both graduate and undergraduate students will work on the project, thus gaining cutting-edge skills and expertise in nanotechnology and science; the PI will work with high school teachers and students in the Atlanta area through Georgia Intern Fellowship for Teachers program and through Georgia Tech's Women in Engineering summer camps; some of the results will be introduced in engineering courses at Georgia Tech as case studies; the PI will participate in Tech to Teaching program that inspires students to choose a teaching career.