Nucleation and Growth of Single-Walled Carbon Nanotubes Catalyzed by Transition Metal Particles

过渡金属颗粒催化单壁碳纳米管的成核与生长

• 批准号: 0804805
• 负责人: Mogus Mochena
• 金额: $ 18万
• 依托单位: Florida Agricultural and Mechanical University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0804805&HistoricalAwards=false
• 关键词: Nucleation; Growth; Single; Walled; Carbon

TECHNICAL SUMMARY:This award supports research and education in theoretical physics in an area related to nucleation and growth of single-walled carbon nanotubes (SWCNT) catalyzed by transition metal particles. The study is motivated by the unusual materials properties of these systems, particularly their remarkable electrical, mechanical, thermal and optical properties. SWCNTs are the best conductors of electricity and heat and have exceptional photophysical and chemical properties. The research intends to provide some of the essential understanding of the processes that occur in creating these materials so that the potential applications of SWCNTs may be realized. The area of particular emphasis includes the nucleation and growth of these materials but in the process researcher will identify processing avenues that make it possible to control the chirality and diameter of a SWCNT, two important parameters that determine whether a SWCNT is semiconducting or metallic.Researchers will use theoretical and computer simulation techniques to better understand the growth process of SWCNT and how to achieve the desired uniformities of coherent and defect-free SWCNTs with controlled diameter, chirality, length and wall structure. This research will focus mainly on analyzing and describing catalyzed CVD technique, which is the most promising of the three major techniques for mass production of SWCNTs. Computer simulations will provide insight into the growth processes which are difficult to monitor experimentally because they occur at temperatures much higher than room temperature, in the range of approximately 400 ? 1000 Kn where the high temperature results in a high pressure, adding to the difficulty of monitoring the atomic level dynamics involved during the experiment despite advanced nanoscale measuring techniques. Computational studies are therefore necessary in order to examine the stages of the growth and pave the way for a more controlled growth of SWCNTsIn order to understand the factors and parameters determining the chirality and diameter of the SWCNTs, rigorous quantum mechanical simulations must be done. We intend to perform all?electron density functional theory (DFT) simulations at the generalized gradient approximation level (GGA). These calculations will serve as benchmarks for ab initio molecular dynamics (MD) calculations which can handle larger systems than the all electron DFT simulations as well as finite temperature calculations. In the final stage of these simulations tight binding molecular dynamics calculations will be performed for larger systems and larger time scales than ab initio MD.The proposed work has both educational and applied impact beyond the basic research. Scientifically, this award will impact related research and applied work to develop carbon based technology at Florida A & M University (FAMU). The computational work will complement the experimental work in the growth of SWCNTS at FAMU Center for Nanoscience and Nanotechnology. The proposed work also will complement the development of the FAMU High Performance Computing Center where a computer cluster is being acquired for high performance computing and the simulations. The educational consequence of this includes the development of computational nanoscience coursework. Participation of minorities in science is supported through this effort. FAMU, one of the leading HBCUs, has one of the four Ph. Ds in physics and this grant will support the training of minority students. The research that has a strong education component involving the training of graduate students and a continuation of the PI's long history of recruiting undergraduates in cutting edge research projects with publishable outcomes.NON-TECHNICAL SUMMARY:This award supports research and education in theoretical physics in an area related to nucleation and growth of single-walled carbon nanotubes (SWCNT). These ultra small tubes are seen as one of the key elements of future nanodevices. The study is motivated by the unusual materials properties of these systems, particularly their remarkable electrical, mechanical, thermal and optical properties. SWCNTs are the best conductors of electricity and heat and have exceptional optical and chemical properties. The research intends to provide some of the essential understanding of the processes that occur in creating these materials so that the potential applications of SWCNTs may be realized. The area of particular emphasis includes the nucleation and growth of these materials but in the process researchers will identify processing avenues that make it possible to control the structure of a SWCNT and the parameters that determine how a SWCNT is conducts electric current.Researchers will use theoretical and computer simulation techniques to better understand the growth process of SWCNT and how to achieve the desired uniformities and defect-free SWCNTs with controlled diameter, length and wall structure. This research will focus mainly on analyzing and describing the most promising techniques for mass production of SWCNTs. Computer simulations will provide insight into the growth processes which are difficult to monitor experimentally because they occur at temperatures much higher than room temperature, and at high pressure, adding to the difficulty of monitoring the experiments despite advanced nanoscale measuring techniques. Computational studies are therefore necessary in order to examine the stages of the growth and pave the way for a more controlled growth of SWCNTs.The proposed work has both educational and applied impact beyond the basic research. Scientifically, this award will impact related research and applied work to develop carbon based technology at Florida A & M University (FAMU). The computational work will complement the experimental work in the growth of SWCNTS at FAMU Center for Nanoscience and Nanotechnology. The proposed work also will complement the development of the FAMU High Performance Computing Center where a computer cluster is being acquired for high performance computing and the simulations. The educational consequence of this includes the development of computational nanoscience coursework. Participation of minorities in science is supported through this effort. FAMU, one of the leading HBCUs, has one of the four Ph. Ds in physics and this grant will support the training of minority students. The research that has a strong education component involving the training of graduate students and a continuation of the PI's long history of recruiting undergraduates in cutting edge research projects with publishable outcomes.

技术摘要：该奖项支持与过渡金属颗粒催化的单壁碳纳米管 (SWCNT) 成核和生长相关领域的理论物理研究和教育。这项研究的动机是这些系统不寻常的材料特性，特别是它们卓越的电气、机械、热和光学特性。单壁碳纳米管是最好的电和热导体，具有优异的光物理和化学特性。该研究旨在提供对这些材料制造过程的一些基本了解，以便实现单壁碳纳米管的潜在应用。特别强调的领域包括这些材料的成核和生长，但在该过程中，研究人员将确定能够控制单壁碳纳米管的手性和直径的加工途径，这两个重要参数决定单壁碳纳米管是半导体还是金属。将使用理论和计算机模拟技术来更好地了解单壁碳纳米管的生长过程，以及如何在受控直径、手性、长度和壁结构的情况下实现相干且无缺陷的单壁碳纳米管的预期均匀性。本研究将主要集中于分析和描述催化CVD技术，该技术是批量生产单壁碳纳米管的三大技术中最有前途的。 计算机模拟将提供对生长过程的深入了解，这些过程很难通过实验监测，因为它们发生的温度远高于室温，范围约为 400 ? 1000Kn，其中高温导致高压，尽管先进的纳米级测量技术增加了监测实验过程中涉及的原子级动力学的难度。因此，有必要进行计算研究，以检查生长阶段并为更受控的单壁碳纳米管生长铺平道路。为了了解决定单壁碳纳米管手性和直径的因素和参数，必须进行严格的量子力学模拟。我们打算在广义梯度近似水平（GGA）上进行全电子密度泛函理论（DFT）模拟。这些计算将作为从头算分子动力学 (MD) 计算的基准，该计算可以处理比全电子 DFT 模拟以及有限温度计算更大的系统。在这些模拟的最后阶段，将针对比从头MD更大的系统和更大的时间尺度进行紧结合分子动力学计算。所提出的工作具有超出基础研究的教育和应用影响。 从科学角度来看，该奖项将影响佛罗里达农工大学 (FAMU) 开发碳基技术的相关研究和应用工作。计算工作将补充 FAMU 纳米科学和纳米技术中心 SWCNTS 生长的实验工作。拟议的工作还将补充 FAMU 高性能计算中心的开发，该中心正在购买计算机集群用于高性能计算和模拟。其教育成果包括计算纳米科学课程的发展。通过这一努力，支持少数群体参与科学。 FAMU 是领先的 HBCU 之一，拥有四个物理学博士学位之一，这笔赠款将支持少数民族学生的培训。该研究具有很强的教育成分，涉及研究生培训，并延续了 PI 招募本科生参与尖端研究项目并可发表成果的悠久历史。非技术摘要：该奖项支持理论物理学的研究和教育与单壁碳纳米管（SWCNT）成核和生长相关的领域。 这些超小管被视为未来纳米器件的关键要素之一。这项研究的动机是这些系统不寻常的材料特性，特别是它们卓越的电气、机械、热和光学特性。单壁碳纳米管是最好的电和热导体，具有卓越的光学和化学特性。该研究旨在提供对这些材料制造过程的一些基本了解，以便实现单壁碳纳米管的潜在应用。特别强调的领域包括这些材料的成核和生长，但在此过程中研究人员将确定能够控制单壁碳纳米管结构的加工途径以及确定单壁碳纳米管如何传导电流的参数。研究人员将使用理论和计算机模拟技术，以更好地了解单壁碳纳米管的生长过程，以及如何在受控的直径、长度和壁结构的情况下获得所需的均匀性和无缺陷的单壁碳纳米管。这项研究将主要集中于分析和描述最有前途的单壁碳纳米管大规模生产技术。 计算机模拟将提供对难以通过实验监测的生长过程的洞察，因为它们发生在远高于室温的温度和高压下，尽管有先进的纳米级测量技术，但增加了监测实验的难度。因此，为了检查生长阶段并为更受控的单壁碳纳米管生长铺平道路，计算研究是必要的。所提出的工作具有基础研究之外的教育和应用影响。 从科学角度来看，该奖项将影响佛罗里达农工大学 (FAMU) 开发碳基技术的相关研究和应用工作。计算工作将补充 FAMU 纳米科学和纳米技术中心 SWCNTS 生长的实验工作。拟议的工作还将补充 FAMU 高性能计算中心的开发，该中心正在购买计算机集群用于高性能计算和模拟。其教育成果包括计算纳米科学课程的发展。通过这一努力，支持少数群体参与科学。 FAMU 是领先的 HBCU 之一，拥有四个物理学博士学位之一，这笔赠款将支持少数民族学生的培训。该研究具有很强的教育成分，涉及研究生培训，并延续了 PI 招收本科生参与尖端研究项目并取得可发表成果的悠久历史。