DMREF: Engineering Strong, Highly Conductive Nanotube Fibers Via Fusion

在这个由化学部门和土木、机械、制造和创新部门资助的nsf设计材料以革新和工程我们的未来（DMREF）项目中，东北大学的Yung Joon Jung、Carol Livermore-Clifford、Moneesh Upmanyu和David Kaeli教授正在研究如何制造高性能碳纤维，这种碳纤维可用于航空航天、高功率密度储能和轻质电缆/布线。制造这种纤维的主要挑战是它们需要机械强度高，同时也是热和电的特殊导体。为了实现这一目标，研究人员正在研究如何将包含许多纳米尺寸的碳管（“碳纳米管”）的网络融合成一个更大、更无缝的结构。正在研究的变量包括将碳纳米管组织到网络中的方法，以及使用电压将碳纳米管融合在一起的方法。实验研究、计算模拟和数据挖掘技术正在被应用于理解融合网络结构和它们如何执行之间的复杂关系。优越的电子、热学和机械性能使碳纳米管网络成为高性能多功能材料的理想构建块，但这些优势在范德华连接网络中被削弱。如果用共价键取代范德华相互作用来制造宏观无缝碳纳米结构，性能应该会显著提高。这个研究项目的重点是一种新的碳纳米结构工程过程，称为纳米管融合。该方法控制整个网络的输入电压，在碳纳米管之间形成共价键分子结（交联），将其转化为更大直径的单壁碳纳米管、多壁碳纳米管或多层石墨烯纳米带，并具有可测量的性能改善。该研究涉及相互依赖的实验、模拟和数据挖掘工作，以实现可扩展的多功能光纤。实验参数包括融合极性、频率、电压、源接通时间和外部温度，以及碳纳米管结构、组装工艺和初始纤维结构。熔融纤维的表征数据和粗粒度原子模拟将物理性质与结构和结构与加工联系起来。统计数据挖掘工作补充了这些工作，以提取纤维加工与其特性之间的复杂关系。该团队正在努力让高中生直接参与研究；为来自不同背景的本科生提供研究机会；并创建关于材料科学和多功能纳米结构网络的专题讨论会。

In this NSF-Designing Materials to Revolutionize and Engineer our Future (DMREF) project funded by the Division of Chemistry and the Civil, Mechanical, Manufacturing and Innovation Division, Professors Yung Joon Jung, Carol Livermore-Clifford, Moneesh Upmanyu, and David Kaeli of Northeastern University are studying how to create high-performance carbon fibers that could be used for applications in aerospace, high power density energy storage, and lightweight cabling/wiring. The main challenge of creating such fibers is that they need to be mechanically strong while also being exceptional conductors of heat and electricity. To accomplish this goal, the researchers are studying how to fuse networks that contain many nanometer-sized carbon tubes ("carbon nanotubes") into a larger, more seamless structure. The variables being studied include ways to organize the carbon nanotubes into the network and to use electric voltage to fuse the carbon nanotubes together. Experimental studies, computational simulations, and data mining techniques are being applied to understand the complex relationships between the structure of the fused networks and how they perform. The combination of superior electronic, thermal, and mechanical properties makes carbon nanotube networks an ideal building block for high-performance multifunctional materials, but these advantages are eroded in van der Waals connected networks. If van der Waals interactions were replaced with covalent bonds to create macroscopic seamless carbon nanostructures, performance should increase significantly. This research project is focusing on a novel carbon nanostructure engineering process called nanotube fusion. The method controls input voltages across the network to create covalently bonded molecular junctions (cross-links) between carbon nanotubes, transforming them into larger diameter single-walled carbon nanotubes, multi-walled carbon nanotubes, or multi-layered graphene nanoribbons with measurable property improvement. The research is engaging interdependent experimental, simulation, and data mining efforts to enable scalable multifunctional fibers. The experimental parameters include fusion polarity, frequency, voltage, source-on-time, and external temperature, as well as carbon nanotube structure, assembly process and initial fiber architecture. Characterization data and coarse-grained atomistic simulation of fused fibers relate physical properties to structure and structure to processing. These efforts are complemented by statistical data mining efforts to extract the complex relationship between fiber processing and their properties. The team is working to involve high school students directly in the research; to enable research opportunities for undergraduates from a diversity of backgrounds; and to create symposia on materials science and on multifunctional nanostructured networks.