Van der Waals and Casimir interactions between atoms and carbon nanotubes

TL;DR

This paper compares van der Waals and Casimir interactions between hydrogen atoms and carbon nanotubes, showing the applicability of graphite dielectric properties and analyzing atom absorption mechanisms at nanometer scales.

Contribution

It demonstrates the validity of using graphite dielectric permittivity for nanotubes with few walls and explores hydrogen atom absorption dynamics near nanotubes.

Findings

Graphite dielectric permittivity applies to nanotubes with 2-3 walls.

Hydrogen atoms are absorbed at separations below 1 nanometer.

Lateral exchange repulsion influences atom positioning and absorption.

Abstract

The van der Waals and Casimir interactions of a hydrogen atom (molecule) with a single-walled and a multiwalled carbon nanotubes are compared. It is shown that the macroscopic concept of graphite dielectric permittivity is already applicable for nanotubes with only two or three walls. The absorption of hydrogen atoms by a nanotube at separations below one nanometer is considered. The lateral force due to exchange repulsion moves the atom to a position above the cell center, where it is absorbed by the nanotube because the repulsive force cannot balance the van der Waals attraction.