Theoretical Characterization of Interfacial Bonding in Self-Assembled Carbon Nanotubes

技术概述：该奖项支持碳纳米管的计算研究和教育。碳纳米管由于其独特的结构、机械和电子特性而具有重要的技术和科学意义。各种化学物质在纳米管表面的组装，为纳米管作为纳米级电子器件的构建块以及聚合物和环氧复合材料的增强剂开辟了道路。原子、化学基团和有机化合物的连接可以通过非共价侧壁功能化来实现，或者通过碳纳米管的共价端基、缺陷和侧壁功能化来实现。通过监测紫外、可见光、红外和拉曼光谱的变化，可以在实验中检测到改变纳米管表面特性的化学污染物的存在。研究将集中于开发和应用计算方法来准确预测缺陷、末端、功能化碳纳米管和自组装纳米管复合物的结构、电子和光学性质。该项目旨在扩展我们对纳米管功能化机制的理解，以及自组装纳米管配合物中化学链接的强度和密度与观察到的其振动和光谱变化之间的关系。所开发的计算算法将应用于附着在不同直径和手性的单壁纳米管上的各种官能团，目的是确定最稳定的组合，适合用于纳米级光电器件和构建具有优越机械性能的纳米复合材料。为了实现这一目标，PI将结合最先进的密度泛函和时间相关的密度泛函理论方法，以及在Beowulf计算机集群上实现的大规模并行计算算法。为了充分利用Beowulf硬件架构，该项目将开发一个专门为并行Beowulf计算机优化的时变密度函数电子结构代码的并行版本。该奖项支持的研究可能会对利用纳米结构材料和复杂计算算法的现代技术的各个领域产生更广泛的影响，特别是在纳米技术、微电子和信息技术方面。该奖项还支持外展和教育活动。研究生和本科生将参与理论建模、纳米结构表征和材料设计领域的跨学科培训和研究。与并行编程、高级计算机模拟和现代纳米结构材料相关的主题将被纳入研究生和本科课程。外联和教育活动将特别针对增加少数民族和代表性不足的群体对学术研究的参与。非技术总结：该奖项支持碳纳米管的计算研究和教育。碳纳米管由于其独特的结构、机械和电子特性而具有重要的技术和科学意义。各种化学物质在纳米管表面的组装，为纳米管作为纳米级电子器件的构建块以及聚合物和环氧复合材料的增强剂开辟了道路。PI将使用基于现代电子结构理论的算法对碳纳米管的特性进行计算计算。这项工作的一部分将涉及该理论的扩展和开发新的计算算法，以便计算原始理论范围之外的属性。该奖项支持的研究可能会对利用纳米结构材料和复杂计算算法的现代技术的各个领域产生更广泛的影响，特别是在纳米技术、微电子和信息技术方面。该奖项还支持外展和教育活动。研究生和本科生将参与理论建模、纳米结构材料表征和材料设计领域的跨学科培训和研究。与并行编程、高级计算机模拟和现代纳米结构材料相关的主题将被纳入研究生和本科课程。外联和教育活动将特别针对增加少数民族和代表性不足的群体对学术研究的参与。

TECHNICAL SUMMARY:This award supports computational research and education on carbon nanotubes. Carbon nanotubes are of significant technological and scientific interest because of their unique structural, mechanical, and electronic properties. The assembly of various chemical species on the surface of nanotubes opens the way for the use of nanotubes as building blocks for nanoscale electronic devices and as reinforcing agents in polymer and epoxy composite materials. The attachment of atoms, chemical groups, and organic compounds can be accomplished by means of noncovalent sidewall functionalization or, alternatively, by covalent end-group, defect, and sidewall functionalization of carbon nanotubes. The presence of chemical contaminants that modify the surface properties of nanotubes can be detected experimentally by monitoring changes in the ultraviolet, visible, infrared, and Raman spectra.Research will focus on developing and applying computational methods for accurate prediction of structural, electronic, and optical properties of defects, termini, functionalized carbon nanotubes, and self-assembled nanotube complexes. The PI aims to extend our understanding of the mechanism of nanotube functionalization and the relation of the strength and density of chemical links in self-assembled nanotube complexes to the change observed in their vibrational and optical spectra. The developed computational algorithm will be applied to a variety of functional groups attached to single-walled nanotubes of different diameter and chirality with the purpose of identifying the most stable combinations suitable for use in nanoscale optoelectronic devices and for building nano-composite materials with superior mechanical properties.To achieve this goal, the PI will combine state-of-the-art density-functional and time-dependent density-functional theoretical methods with massively parallel computational algorithms implemented on Beowulf computer clusters. In order to take full advantage of Beowulf hardware architecture, the project will develop a parallel version of the time-dependent density-functional electronic structure code specifically optimized for parallel Beowulf computers.The research supported by this award may have broader impacts on various areas of modern technology that utilize nanostructured materials and employ complex computational algorithms, particularly on nanotechnology, microelectronics, and information technology.This award also supports outreach and education activities. Graduate and undergraduate students will be involved in interdisciplinary training and research in the fields of theoretical modeling, characterization of nanostructures, and materials design. Topics related to parallel programming, high-level computer simulations, and modern nanostructured materials will be incorporated in the graduate and undergraduate-level curriculum. The outreach and education activities will be specifically directed at increasing the participation of minorities and underrepresented groups in academic research.NON-TECHNICAL SUMMARY:This award supports computational research and education on carbon nanotubes. Carbon nanotubes are of significant technological and scientific interest because of their unique structural, mechanical, and electronic properties. The assembly of various chemical species on the surface of nanotubes opens the way for the use of nanotubes as building blocks for nanoscale electronic devices and as reinforcing agents in polymer and epoxy composite materials. The PI will perform computational calculations of the properties of Carbon nanotubes using algorithms based on modern electronic structure theory. Part of this work will involve extensions of that theory and developing new computational algorithms to enable calculations of properties outside the scope of the original theory.The research supported by this award may have broader impacts on various areas of modern technology that utilize nanostructured materials and employ complex computational algorithms, particularly on nanotechnology, microelectronics, and information technology.This award also supports outreach and education activities. Graduate and undergraduate students will be involved in interdisciplinary training and research in the fields of theoretical modeling, characterization of nanostructured materials, and materials design. Topics related to parallel programming, high-level computer simulations, and modern nanostructured materials will be incorporated in the graduate and undergraduate-level curriculum. The outreach and education activities will be specifically directed at increasing the participation of minorities and underrepresented groups in academic research.