On the Possible Nature of Armchair-Zigzag Structure Formation and Heat Capacity Decrease in MWCNTs.

Alexander Ponomarev,Anna Belosludtseva,Nadezhda Bobenko,Valeriy Egorushkin,Maksym Barabashko,Anastasiya Rezvanova

doi:10.3390/ma15020518

Abstract

Structural disorder and temperature behavior of specific heat in multi walled carbon nanotubes (MWCNTs) have been investigated. The results of X-ray diffractometry, Raman spectroscopy, and transmission electron microscopy (TEM) images are analyzed. The thermodynamic theory of the zigzag-armchair domain structure formation during nanotube synthesis is developed. The influence of structural disorder on the temperature behavior of specific heat is investigated. The size of domains was estimated at ~40 nm. A decrease in heat capacity is due to this size effect. The revealed dependence of the heat capacity of MWCNTs on the structural disorder allows control over thermal properties of nanotubes and can be useful for the development of thermoelectric, thermal interface materials and nanofluids based on them.

Highlights

Capacity Decrease in multi walled carbon nanotubes (MWCNTs).Carbon nanotubes (CNTs) are the new generation of materials with a wide range of technological applications, one of which is the production of thermoelectric [1] and thermal interface materials [2], nanofluids [3], etc. designed for energy efficiency
Structural features depend on the synthesis methods, among which are arc discharge (AD), laser vaporization (LV), and chemical vapor deposition (CVD) [4]
We experimentally study the structure (X-ray diffraction and Raman spectroscopy), discuss transmission electron microscopy (TEM) images and temperature dependences of the specific heat of SWCNTs and MWCNTs

Summary

Introduction

Capacity Decrease in MWCNTs.Carbon nanotubes (CNTs) are the new generation of materials with a wide range of technological applications, one of which is the production of thermoelectric [1] and thermal interface materials [2], nanofluids [3], etc. designed for energy efficiency. Carbon nanotubes (CNTs) are the new generation of materials with a wide range of technological applications, one of which is the production of thermoelectric [1] and thermal interface materials [2], nanofluids [3], etc. In this case, the CNT structure plays an important role. Structural features depend on the synthesis methods, among which are arc discharge (AD), laser vaporization (LV), and chemical vapor deposition (CVD) [4]. The CVD method is most widely used due to its simplicity, ability to produce materials with more than 95% CNTs, low energy consumption, and the possibility of controlling the structure via the synthesis mode [5]. The physical and chemical properties of nanotubes are determined by their structure

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Conclusion