CAREER: Overcoming Heterogeneity: Ultra-monodisperse Semiconducting Carbon with Parts per Million and Billion Polydispersity

职业：克服异质性：具有百万分之一和十亿分度多分散性的超单分散半导体碳

• 批准号: 1350537
• 负责人: Michael Arnold
• 金额: $ 57.5万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-15 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1350537&HistoricalAwards=false
• 关键词: CAREER; Overcoming; Heterogeneity; Ultra; monodisperse

TECHNICAL SUMMARY:The overarching objective of this project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, is to uncover and develop fundamentally new ways for realizing ultra-monodisperse semiconducting single-walled carbon nanotubes. This work will explore novel strategies in the post-synthetic separation and sorting of nanotubes using nanotube-differentiating conjugated polymers, while at the same time implement metrologies for quantifying monodispersity that are needed to advance the differentiation and sorting. Certain classes of conjugated polymers such as polyfluorenes are unusually effective semiconducting nanotube-discriminating agents, for example discerning by electronic-type so powerfully that under the proper conditions the conjugated polymers will not measurably disperse nanotubes that are metallic. Currently, very little is known about these polymers and how they interact with nanotubes. However, with a better understanding of the materials chemistry of nanotube-polymer interactions, it should become possible to realize nanotubes that that are so monodisperse that their bandgap polydispersity can be counted in only parts per million and their electronic-type polydispersity in parts per billion (whereas current nanotube monodispersity is typically measured in parts per hundred). Focused research will be pursued in 4 areas: (1) Exploration and implementation of metrology that can quantify "impurity" nanotubes at vanishing concentrations; (2) Fundamental experimentation designed to understand the materials chemistry and thermodynamics of nanotube / differentiating polymer binding; (3) Investigation of the role of defects on polymer-nanotube binding; and (4) Implementation of single- and multi-step dispersion and post-dispersion differentiation. NON-TECHNICAL SUMMARY:Since their discovery in 1991, carbon nanotubes have tantalized scientists and the general public, as well, due to their unique structure and exceptional properties. These materials promise to help overcome many of society's grand challenges in electronics, energy, and medicine. However, this promise has not yet been realized because of nanotubes' heterogeneity, which is both physical and electronic. Recently, a promising class of polymers has been discovered that can be used to select for specific types of carbon nanotubes and thereby dramatically reduce their heterogeneity. This project will uncover fundamental details regarding the materials chemistry of the interactions between nanotubes and the polymers. The understanding that is gained will then be used to create carbon nanotubes that are sufficiently ultra-monodisperse to enable applications that have long been hyped but inhibited by heterogeneity. In conjunction with the technical project, outreach will be conducted to inspire youth to enter science, technology, engineering, and mathematics (STEM) fields and increase educational opportunities for under-represented groups. For example, a hands-on STEM-based workshop for middle school students entitled "E3-Engineering, Energy, and the Environment" will be created and implemented. The workshop will engage students in materials science topics with an energy and environmental hook (such as energy efficient or energy harvesting materials), teach creative problem-solving, inspire the next-generation of scientists and engineers, and involve undergraduate and graduate students in mentoring and outreach experiences.

技术摘要：该项目的总体目标在材料研究部的固态和材料化学计划的支持下，是为了揭示和开发从根本上实现超单分散分散的新方法，以半导体的半导体单壁碳纳米管。这项工作将使用纳米管划分的共轭聚合物探索纳米管后分离和分类纳米管的新型策略，同时实现了量化分散和分类所需的单分散性的计量学。某些类别的共轭聚合物（例如多氟烯）是异常有效的半导体纳米管划分的剂，例如，通过电子型辨别的是如此有力地辨别，以至于在适当的条件下，共轭聚合物将无法测量地分散的纳米管。目前，这些聚合物以及它们如何与纳米管相互作用知之甚少。然而，有了更好地了解纳米管聚合物相互作用的材料化学，应该有可能意识到纳米管是如此单分散的纳米管，以至于它们的带隙多分散性只能以百万分之十的零件计数及其电子型型多级别的零件计数，而这些部分的零件是每10亿（而当前的纳米管单位均具有典型的零件，则是典型的一度均等的一百次。重点研究将在4个领域进行：（1）探索和实施可以在消失的浓度下量化“杂质”纳米管的计量学； （2）旨在了解纳米管 /分化聚合物结合的材料化学和热力学的基本实验； （3）研究缺陷对聚合物 - 纳米管结合的作用； （4）实施单步分散和分散后分化。非技术摘要：自1991年发现以来，碳纳米管也具有诱人的科学家和普通公众，因为它们的独特结构和卓越特性。这些材料有望帮助克服社会在电子，能源和医学方面的许多巨大挑战。但是，由于纳米管的异质性，既是物理和电子的，尚未实现这一承诺。最近，已经发现了一类有希望的聚合物，可用于选择特定类型的碳纳米管，从而大大减少其异质性。该项目将发现有关纳米管与聚合物之间相互作用的材料化学的基本细节。然后，获得的理解将用于创建足够超单分散的碳纳米管，以实现长期以来一直炒作但被异质性抑制的应用。与技术项目一起，将进行外展活动，以激发青年进入科学，技术，工程和数学（STEM）领域，并增加代表性不足的群体的教育机会。例如，将创建和实施一个基于动手的基于STEM的研讨会，名为“ E3工程，能源和环境”。研讨会将吸引学生参与能源和环境钩子（例如节能或能源收集材料），讲授创造性问题的材料科学主题，激发科学家和工程师的下一代，并让本科生和研究生参与指导和外展经验。