Tuning structural and thermal conductivity of carbon nanotubes under strain effects

Abstract

Equilibrium molecular dynamics (EMD) computations have been performed to estimate the thermal conductivity (λ) of armchair and chiral single-walled carbon nanotubes (SWCNTs) under the influence of varying axial compressive and tensile strains ±γ(%). For the first time, the present work provides new outcomes of structural behavior of SWCNTs linked through λ, considering the combinations of nanotube length (L), system temperature (T) and effects of varying ±γ(%). A radial distribution function (RDF) test has performed in order to investigate the structure analysis of armchair and chiral SWCNTs with different compressive (−1% – −10%) and tensile (+1% – +10%) strain sequences at the extreme L (= 100 Å and 1900 Å) and T (=300 K). The RDF and visualization tests indicate that both configurations are more tunable under tensile strain but the buckling processes of armchair SWCNTs are less evident as compared to chiral configurations. The simulation data shows that the λ(T, L) increases as L extends and it also confirmed through slight increase in RDF peaks, while the λ(T, L) of chiral SWCNTs is high compared to armchair SWCNTs for a complete range of T at L (= 100 Å and 1900 Å). However, the calculations indicate that the delta change in λ(T, L) of armchair SWCNTs is more than the chiral one, as expected. The simulation data demonstrates that the positions of the highest and lowest values of the thermal conductivity of the chiral SWCNTs shift to a longer L as compared to the armchair SWCNTs. The λ(T, L) of SWCNTs remains high for -γ(%) range at short L (=100 Å) due to less broaden shift in RDF peaks but slightly higher for +γ(%) range at longer L (=1900 Å) due to boarder shift in RDF peaks. Moreover, the present simulation results obtained from EMD approach are found to be in reasonable agreement with those obtained via the previous known numerical results.