INFLUENCE OF DOMAIN STRUCTURE ON THERMAL PROPERTIES OF CARBON NANOTUBES

In this work, we studied the structure of carbon nanotubes (CNTs) and its effect on the heat capacity of CNTs. We show that single-wall CNTs (SWCNTs) contain zigzag structures that are ~ 200 nm in size and the surface of multi-walled CNTs (MWCNTs) is formed by zigzag-armchair crystallites that are ~ 40 nm in size. A decrease in the size of the crystallites in MWCNTs leads to a higher density of domain interfaces that scatter phonons, resulting in an increase in the lower cutoff frequency of these phonons and 10% decrease in the heat capacity of the MWCNTs compared to SWCNTs. The revealed dependence of the heat capacity on the structural disorder allows one to control of the thermal properties of nanotubes and may be useful in the development of thermoelectric and thermal interface materials. © 2023 by Begell House, Inc.