Collaborative Research: Diameter and Chirality Control and Regrowth of Single-Walled Carbon Nanotubes

合作研究：单壁碳纳米管的直径和手性控制以及再生

• 批准号: 0828771
• 负责人: Lisa Pfefferle
• 金额: $ 29.99万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0828771&HistoricalAwards=false
• 关键词: Collaborative; Research; Diameter; Chirality; Control

PROPOSAL NUMBER: 0828771 (collaborative with 0828824)PRINCIPAL INVESTIGATOR: Pfefferle, Lisa (Papadimitrakopolous, Fotios)INSTITUTION: Yale University (U. Connecticut)Collaborative Proposal: Diameter and Chirality Control and Re-growth of Single-Walled Carbon Nanotubes Intellectual Merit: Synthesizing useful quantities of uniform (n,m) identity single-walled carbon nanotubes (SWNT) is a serious challenge, necessary for advanced electronic applications and a major limitation facing high-end SWNT applications. An attractive route involves the isolation of small batches of the given SWNT, followed by cutting into "seeds", achieving effective tube end catalyst templating, and regrowth from the ends maintaining the original (n,m)-chirality. Recent exciting methodologies involving molecular manipulation and templating propose to address this separation and regrowth challenge, but these are inherently complex and difficult to scale, and it is not clear whether seed chirality is maintained and whether regrowth preferentially favors certain species. We have developed preliminary data that it is feasible to reactively template the growth catalyst on the SWNT ends, offering the potential for substantial easing of the complexity of the catalyst templating process with a more effective and scalable process. By loading catalyst on the inside of shortened SWNT "seeds", and adding reactant (e.g. H2) at proper conditions, we are producing SWNT "seeds" with catalyst templated for effective lengthening in a regrowth process with the bulk identity distribution maintained. Two effective templating reagents include hydrogen through methanation or COB2B through reverse disproportionation. Temperature is key, and depends on the reagent/catalyst pair and also on the tube identity. This approach makes chemical sense as it mimics the SWNT growth process itself. We present proof of principle of gas phase regrowth of dispersed SWNT seeds. Advantages include process scalability, fidelity and reduced post-processing for lower defect rate. Regrowth also will be probed using P13PC-enriched SWNT seeds, with given (n,m)-abundance profiles, to establish whether P12PC-enriched regrowth is initiated at the seed-tips and chirality is maintained. We will investigate the regrowth process as a function of different diameter, chirality and metallicity of SWNT, produced by: (i) our previously demonstrated synthesis of narrow-diameter distribution SWNT and (ii) SWNT fractionated by the co-PI according to type, diameter and chirality. We have demonstrated the ability to produce SWNT samples with different (n,m)-abundances, narrow diameter distribution and mean diameter varying from 0.6 to 1.7 nm. The proposed effort combines complementary expertise of the PI in nanotube synthesis and the extensive specialization of the co-PI in nanotube separation and quantitative (n,m)-characterization using photoluminescence and tunable-laser resonance Raman spectroscopy. This combined expertise will allow exploring the mechanism of our regrowth process along with optimization. Mechanism studies will also take advantage of the PIs work on X-ray absorption analysis of SWNT growth catalysts under reaction conditions. Broader Impacts: Chemical production of specific (n,m) SWNT would revolutionize the SWNT device industry. The method to be explored is inexpensive, requires little post processing and would put good quality SWNT in the hands of many more researchers. SWNT also provides an exciting material for interesting undergraduates in research: our activities include developing a lab-based course involving students from local non-PhD granting institutions, involving participation in a research project on water remediation and the interaction of SWNT with microbes. Students will see how SWNT are made, participate in functionalization for water solubility, and do experiments in their home lab to assess SWNT toxicity to a target microbe. This will be linked to the Co-PIs involvement in a Connecticut-wide course development in Nanotechnology for undergraduates. This includes developing UConn's "Nanovan-Project", where an AFM microscope is loaded into a van and driven to high schools for live demonstrations including a SWNT demonstration.

提案编号：0828771（与 0828824 合作）主要研究员：Pfefferle, Lisa (Papadimitrakopolous, Fotios) 机构：耶鲁大学（康涅狄格州）合作提案：单壁碳纳米管的直径和手性控制及再生长 智力优势：合成有用数量均匀（n，m）的单壁碳纳米管（SWNT）是一个严峻的挑战，是先进电子应用所必需的，也是高端SWNT应用面临的主要限制。一种有吸引力的途径包括分离小批量的给定单壁碳纳米管，然后切割成“种子”，实现有效的管端催化剂模板化，并从端部重新生长，保持原始的（n，m）手性。最近涉及分子操作和模板化的令人兴奋的方法提出来解决这种分离和再生挑战，但这些方法本质上很复杂且难以规模化，并且尚不清楚种子手性是否得以维持以及再生是否优先有利于某些物种。我们已经开发出初步数据，表明在单壁碳纳米管末端反应性地模板化生长催化剂是可行的，这为通过更有效和可扩展的过程大幅降低催化剂模板化过程的复杂性提供了潜力。通过在缩短的单壁碳纳米管“种子”内部加载催化剂，并在适当的条件下添加反应物（例如氢气），我们正在生产单壁碳纳米管“种子”，其催化剂模板可在再生过程中有效延长，同时保持本体分布。两种有效的模板剂包括通过甲烷化产生的氢气或通过反向歧化产生的 COB2B。温度是关键，取决于试剂/催化剂对以及管的特性。这种方法具有化学意义，因为它模仿了单壁碳纳米管生长过程本身。我们证明了分散的单壁碳纳米管种子气相再生的原理。优点包括流程可扩展性、保真度和减少后处理以降低缺陷率。还将使用富含 P13PC 的 SWNT 种子（具有给定的 (n,m) 丰度分布）来探测再生，以确定富含 P12PC 的再生是否在种子尖端启动并保持手性。我们将研究再生过程作为不同直径、手性和金属性的单壁碳纳米管的函数，产生的：（i）我们之前演示的窄直径分布单壁碳纳米管的合成和（ii）由共PI根据类型分级的单壁碳纳米管，直径和手性。我们已经证明了生产具有不同 (n,m) 丰度、窄直径分布和平均直径从 0.6 到 1.7 nm 变化的 SWNT 样品的能力。拟议的工作结合了 PI 在纳米管合成方面的互补专业知识和 co-PI 在使用光致发光和可调谐激光共振拉曼光谱进行纳米管分离和定量（n，m）表征方面的广泛专业知识。这种综合的专业知识将允许探索我们的再生过程和优化的机制。机理研究还将利用 PI 在反应条件下对 SWNT 生长催化剂进行 X 射线吸收分析的工作。更广泛的影响：特定 (n,m) SWNT 的化学生产将彻底改变 SWNT 器件行业。所探索的方法成本低廉，几乎不需要后处理，并且可以将高质量的单壁碳纳米管交给更多的研究人员。 SWNT 还为感兴趣的本科生提供了令人兴奋的研究材料：我们的活动包括开发基于实验室的课程，让来自当地非博士学位授予机构的学生参加，涉及水修复和 SWNT 与微生物相互作用的研究项目。学生将了解如何制作单壁碳纳米管，参与水溶性功能化，并在家庭实验室中进行实验以评估单壁碳纳米管对目标微生物的毒性。这将与联合PI参与康涅狄格州本科生纳米技术课程开发有关。这包括开发康涅狄格大学的“Nanovan-Project”，将 AFM 显微镜装载到一辆货车中并开往高中进行现场演示，包括 SWNT 演示。