Adhesion between two carbon nanotubes: Insights from molecular dynamics simulations and continuum mechanics

Abstract

Radial deformation in the adhesion between carbon nanotubes (CNTs) significantly affects the structures and properties of their high-performance assemblies. In this work, both classical molecular dynamics (MD) simulations and continuum analysis are employed to investigate the parallel adhesion between two identical and non-identical CNTs. CNTs are equivalent to infinitely long cylindrical shells, and the stable adhesion is a result of the balance between the elastic strain energy and the inter-tube van der Waals (vdW) interactions. Applying the principle of minimum potential energy and the energy variation approach, we derive the governing equations and boundary conditions. Agreement of the theoretical adhesive configurations with the results of MD simulations is relatively good. We investigate the roles of diameters, chiralities, numbers of walls on the inter-tube adhesion both quantitatively and qualitatively. We further reveal that, for two CNTs with considerably different radii or bending rigidities, the CNT experiencing greater radial deformation is likely to collapse to the other due to the inside vdW attractions. The present investigation could provide guidance for the design of nanostructures and regulating the structures and properties of CNT-based assemblies.