In Situ Tests of Multiwalled Carbon Nanotubes with Strength Close to Theoretical Predictions  

作　　者：彭倍 Horacio D. Espinosa 

机构地区：[1]Center for Micro and Nano Electromechanical Systems, University of Electronic Science and Technology of China, Chengdu 610054 [2]Micro and Nano Mechanics Laboratory, Northwestern University, Illinois 60208, USA

出　　处：《Chinese Physics Letters》2009年第1期194-197,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No 50801009, and the National Science Foundation of USA （CMMI 0555734 and CHE-0550497）.

摘　　要：Using MEMS technology and transmission electron microscopy we show experimentally multiwalled carbon nanotubes with a mean fracture strength of larger than 100 GPa, which exceeds the earlier observations by a factor of approximately 3. These results are in excellent agreement with quantum-mechanical estimations. This performance is made possible by omitting chemical treatments from the sample preparation process, thus avoiding the formation of defects. High-resolution imaging is used to directly determine the number of fractured shells and the ehirality of the outer shell. Electron irradiation at 200keV for 10, 100 and 1800s lead to improvements of the maximum sustainable loads by factors of 2.4, 7.9 and 11.6 compared with non-irradiated samples of similar diameter. This effect is attributed to crosslinking between the shells. This procedure is a cost effective way of customizing the properties of multiwall nanotubes for many applications of interest ranging from nanocomposites to nanodevices.Using MEMS technology and transmission electron microscopy we show experimentally multiwalled carbon nanotubes with a mean fracture strength of larger than 100 GPa, which exceeds the earlier observations by a factor of approximately 3. These results are in excellent agreement with quantum-mechanical estimations. This performance is made possible by omitting chemical treatments from the sample preparation process, thus avoiding the formation of defects. High-resolution imaging is used to directly determine the number of fractured shells and the ehirality of the outer shell. Electron irradiation at 200keV for 10, 100 and 1800s lead to improvements of the maximum sustainable loads by factors of 2.4, 7.9 and 11.6 compared with non-irradiated samples of similar diameter. This effect is attributed to crosslinking between the shells. This procedure is a cost effective way of customizing the properties of multiwall nanotubes for many applications of interest ranging from nanocomposites to nanodevices.

关 键 词：field emission molybdenum dioxide enhancement factor 

分 类 号：TB383[一般工业技术—材料科学与工程]