Fullerene filling modulates carbon nanotube radial elasticity and resistance to high pressure

Abstract

The high pressure behavior of carbon nanotubes (CNTs) filled with fullerenes (C₆₀@CNTs) is investigated systematically using molecular mechanics and molecular dynamics simulations. It is shown that the C₆₀ filling can increase the transition pressure (P_c) of intrinsic CNTs and optimize the radial elasticity of CNTs. The C₆₀ filling increases the P_c of CNT(17, 0) by a factor of ∼25, and the P_c of CNT(10, 10) by a factor of ∼5. An inelastic CNT(17, 0) can be transformed into a superelastic CNT(17, 0) by filling C₆₀ into CNTs. Moreover, C₆₀@CNTs with larger diameters (21.76 Å > d > 13.56 Å) show the better radial elasticity compared with intrinsic CNTs. These characteristics can make C₆₀@CNTs possess potential applications in pressure sensors, electromechanical oscillators, nanotube memory etc. In addition, C₆₀@CNTs with larger diameters (21.76 Å > d > 13.56 Å) undergo two structure transitions under high pressure, which is well in agreement with the experimental results. The Lennard–Jones potential can describe the interaction between C₆₀ and CNT well and explain radial collapse and recovery properties of C₆₀@CNT completely, which can provide theoretical guidance for experimental results.