Nanoscale Structural Rearrangement and Strain Softening in Ultra-Pure Nanotube Membranes

超纯纳米管膜中的纳米级结构重排和应变软化

• 批准号: 0969155
• 负责人: Erik Hobbie
• 金额: $ 29.9万
• 依托单位: North Dakota State University Fargo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0969155&HistoricalAwards=false
• 关键词: Nanoscale; Structural; Rearrangement; Strain; Softening

Thin films of single-walled carbon nanotubes show considerable promise for applications that require flexible conductive coatings, and the deformation mechanics of nanotube-nanotube contacts is what ultimately dictates the strength and durability of such films. Electronic type can have a significant impact on the strength of these contacts through the nature of the van der Waals interactions between contacted nanotubes. In work supported by this grant, we are separating nanotubes into metallic and semiconducting fractions and assembling them as pristine membranes on flexible polymer surfaces. Strain-induced structural changes will be investigated over a broad range of length scales using a diverse set of measurement techniques. To interpret these measurements, we will use coarse-grained molecular dynamics simulations of nanoscale deformation in two-dimensional rigid-rod networks with adjustable friction and tunable interaction potentials. These simulations allow us to model anisotropic changes in network elasticity over a wide range of experimentally relevant parameters, providing critical insight into the local structural changes that govern the mechanics of flexible nanotube films.The broader impact of this work can be found in both the commercial sector and the classroom. The insight gained will lead to improvements in the mechanical performance and durability of nanotube films, with emerging applications in photovoltaic devices and fuel-cell membranes. Undergraduate research participation is a significant part of this research. Our group has an established record of mentoring undergraduates, including women and under-represented minorities, through challenging research projects that culminate in publications in leading scientific journals. The insight we gain will also be directly incorporated into the graduate and undergraduate curriculum in Materials and Nanotechnology at NDSU, a newly established interdisciplinary program that spans the departments of Physics, Mechanical Engineering, Civil Engineering, and Coatings & Polymeric Materials.

单壁碳纳米管薄膜在需要柔性导电涂层的应用中显示出巨大的前景，而纳米管-纳米管接触的变形力学最终决定了此类薄膜的强度和耐用性。通过接触纳米管之间范德华相互作用的性质，电子类型可以对这些接触的强度产生重大影响。在这笔拨款支持的工作中，我们将纳米管分离成金属和半导体部分，并将它们组装成柔性聚合物表面上的原始膜。将使用多种测量技术在广泛的长度范围内研究应变引起的结构变化。为了解释这些测量结果，我们将使用具有可调摩擦力和可调相互作用势的二维刚性杆网络中纳米级变形的粗粒度分子动力学模拟。这些模拟使我们能够在各种实验相关参数上对网络弹性的各向异性变化进行建模，从而为控制柔性纳米管薄膜力学的局部结构变化提供重要的见解。这项工作的更广泛影响可以在商业领域和课堂中找到。所获得的见解将改善纳米管薄膜的机械性能和耐用性，并在光伏器件和燃料电池膜中得到新兴应用。本科生的研究参与是这项研究的重要组成部分。我们的团队拥有通过富有挑战性的研究项目来指导本科生（包括女性和代表性不足的少数族裔）的良好记录，这些项目最终在领先的科学期刊上发表论文。我们获得的见解也将直接纳入 NDSU 材料和纳米技术研究生和本科生课程中，这是一个新设立的跨学科项目，涵盖物理、机械工程、土木工程以及涂料和聚合物材料系。