Delivered by Ingenta to: Sibley Library, Eastman School of Music IP: 5.101.219.97 On: Tue, 27 Jun 2017 06:12:32 Copyright: American Scientific Publishers Copyright © 2017 American Scientific Publishers All rights reserved Printed in the United States of America Article Journal of Nanoscience and Nanotechnology Vol. 17, 5252–5260, 2017 www.aspbs.com/jnn Coaxial Boron-Nitride/Carbon Nanotubes as a Potential Replacement for Double-Walled Carbon Nanotubes for High Strain Applications Anirban Chandra 1† , N. M. Anoop Krishnan 2 ∗† , Puneet Kumar Patra 3† , and Debraj Ghosh 4 1 Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, WB 721302, India 2 Department of Civil Engineering, University of California Los Angeles, CA 90095-1593, USA 3 Advanced Technology Development Center, Indian Institute of Technology Kharagpur, WB 721302, India 4 Department of Civil Engineering, Indian Institute of Science Bangalore, KA 560012, India Recently fabricated coaxial Boron Nitride/Carbon nanotubes offer a potential replacement for double walled carbon nanotubes (DWCNTs) and boron nitride nanotubes (DWBNTs). However, an under- standing of the mechanical response is imperative before using coaxial NTs for any device based application. In the present work, the buckling behavior of CNTs embedded within BNTs (C@BN) and BNTs embedded within CNTs (BN@C) under uniaxial compressive loading at 300 K is explored using molecular dynamics simulations. The nanotubes are modeled using the Tersoff three body potential, with the inter-wall interaction estimated using the Lennard-Jones potential. Our results identify a critical interlayer spacing corresponding to which the nanotubes display maximum buckling force and strain. Associated mechanism reveals an interesting radius and chirality dependent buck- ling behavior. The BN@C nanotubes are found to be superior to others in terms of buckling strain, while exhibiting buckling strength comparable with DWCNTs. These superior properties make them a potential candidate for replacing DWCNTs in applications that demand large compressive strains. The inner CNTs of the C@BN nanotubes act like a reinforcing agent, and therefore, these nano- tubes have larger buckling strength than DWBNTs. However, their good buckling strength is marred by a substantial reduction in buckling strain, making them an inferior replacement for DWBNTs in applications requiring large-strains. Keywords: Coaxial Nanotubes, Buckling Strength, Molecular Dynamics. 1. INTRODUCTION The last two decades saw a surge of interest in nanoscience and nanotechnology wherein, the materi- als are manipulated at the atomistic length scale to tailor their properties at various length scales. This was expedited by the discovery and synthesis of nano- tubes (NTs), both Carbon (CNT) and Boron-Nitride (BNT), which provided an exciting boost to the field of nanoscale engineering. Because of their excellent mechan- ical properties 1–3 along with good chemical and thermal properties 4–6 the nanotubes have been used in several applications like sensor development, 7–11 protective shield for nanomaterials 12 hydrogen storage, 13–17 sorption of ∗ Author to whom correspondence should be addressed. † These three authors contributed equally to this work. gases, 18 19 water purification, 20 21 and fabrication of new composite materials. 22 23 However, hidden beneath the structural similarities of different nanotubes, lie contrasting mechanical, electronic, and thermal characteristics. This motivated the search for hybrid- or hetero-nanostructures, wherein a superior composite nanostructure is obtained by ensuring the integration of the appropriate properties of two different nanostructures. One of such recent hetero-nanostructure is the coax- ial system of CNTs and BNTs. Recent experiments sug- gest that it is possible to create BNTs within CNTs (BN@C nanotubes). 24 Coaxial C@BN nanotubes have also transcended the theoretical realms, and have been realized experimentally by several techniques, the promi- nent amongst them being: (i) peapods C 60 @BNT method, where the C 60 molecules coalesce to form a single-walled 5252 J. Nanosci. Nanotechnol. 2017, Vol. 17, No. 8 1533-4880/2017/17/5252/009 doi:10.1166/jnn.2017.13819