Effect of morphology on the strain recovery of vertically aligned carbon nanotube arrays: An in situ study
Abstract
We report on the distinctly different mechanical responses of two vertically aligned carbon nanotube (VACNT) films, subjected to large displacement (up to 70 μm) flat punch indentations. The VACNT films were synthesized using the same chemical vapor deposition (CVD) technique but for varying reaction times, which resulted in their different thicknesses (480 and 160 μm, respectively) and morphologies. In situ tests reveal that the shorter, more aligned VACNT film deforms via an instantaneous vertical shearing of the material directly underneath the indenter tip, which is manifested as a rapid displacement burst in the load–displacement response when tested at rates of 100 nm/s and above. The resultant buckles were of a more permanent nature leading to their low recoverability (22–40%). In contrast, we find the thicker, more tortuous VACNT film to show a higher (∼80%) recovery and a more compliant response. These differences in the mechanical response of the VACNTs are discussed in the framework of foam-like deformation with a particular emphasis on their different morphological features, namely density and tortuosity.
Additional Information
© 2013 Published by Elsevier Ltd. Received 7 March 2013. Accepted 22 June 2013. Available online 2 July 2013. We acknowledge Prof. Julia R. Greer for helpful discussions and for providing access to testing facilities. SP gratefully acknowledges support from the W.M. Keck Institute for Space Studies Postdoctoral Fellowship program for this work. JRR acknowledges the Army Research Office and the Department of Defense for funding via a National Defense Science & Engineering Graduate fellowship during the course of this work. CD acknowledges support from the Institute for Collaborative Biotechnologies under contract W911NF-09-D-0001 with the Army Research Office. We acknowledge critical support and infrastructure provided for this work by the Kavli Nanoscience Institute at Caltech.Additional details
- Eprint ID
- 42189
- DOI
- 10.1016/j.carbon.2013.06.083
- Resolver ID
- CaltechAUTHORS:20131101-105544944
- Keck Institute for Space Studies (KISS)
- National Defense Science and Engineering Graduate (NDSEG) Fellowship
- Army Research Office (ARO)
- W911NF-09-D-0001
- Kavli Nanoscience Institute
- Created
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2013-11-01Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Kavli Nanoscience Institute, Keck Institute for Space Studies