Mechanical Behavior of Single and Bundled Defect-Free Carbon Nanotubes

作     者：Yunxiang Bai Hongjie Yue Rufan Zhang Weizhong Qian Zhong Zhang Fei Wei 

作者机构：Beijing Key Laboratory of Green Chemical Reaction Engineering and TechnologyDepartment of Chemical EngineeringTsinghua UniversityBeijing 100084China CAS Key Laboratory of Nanosystem and Hierarchical Fabrication and CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China 

出 版 物：《Accounts of Materials Research》 (材料研究述评（英文）)

年 卷 期：2021年第2卷第11期

页      面：998-1009页

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：We thank Prof.Dezheng Wang for English editing.This work was supported by Foundation for the National Basic Research P rogram of Ch ina grant s 2016YFA0200102,2020YFC2201100 2020YFA0210700 National Natural Science Foundation of China grants 21636005,22075163,and 51872156 

主　　题：singularity fatigue Bundle 

摘      要：CONSPECTUS:Superstrong materials can be utilized in many fields such as bulletproof vests,airframes,suspension bridges,flywheel energy storage,*** one of the strongest materials,carbon nanotubes(CNTs)can potentially be used to fabricate superstrong ***,the tensile strength of CNTs is impaired a lot by defects,and the CNT fibers prepared so far have strengths much lower than that of a single CNT,showing a“size effect.The conventional study of solid mechanics is usually based on the assumption that materials contain ***-free ultralong CNTs can hopefully help us avoid the“size effectof nanomaterials and produce superstrong CNT *** would also provide a system for the study of the mechanical behavior of ideal solids with a nonlocalized“quantum stress singularity.In this Account,we discuss our recent studies on the mechanical behavior of defect-free single CNTs and CNT ***,we introduce the defect-free structure of ultralong CNTs,which is one type of ideal ***,we review the investigation of the static tensile properties and dynamic fatigue resistance and their temperature-dependence of single centimeters long defect-free *** results showed that defect-free CNTs have superior comprehensive mechanical properties,including superstrength,-toughness,*** from traditional materials,the fatigue lifetime and fracture of CNTs are dominated by the first single-bond-sized defect(quantum stress singularity),showing“superbrittleness.Third,by using a gas flow focusing in situ synthesis method as well as a synchronous tightening and relaxing strengthening strategy,we successfully fabricated CNT bundles with tensile strengths approaching that of single CNTs and showed that the“size effectcan be *** addition,the advantages and promising future of using CNTs in flywheel energy storage are ***,we provide our perspectives on the challenges and future directions in this field.