Molecular dynamics study of the influence of functionalization on the elastic properties of single and multiwall carbon nanotubes

The effect of carboxylation on axial Young’s modulus of carbon nanotubes is investigated using a molecular dynamics (MD) approach. COMPASS force field is used to model the interatomic interactions in single wall (SWCNT) and multiwall carbon (MWCNT) with different amounts of –COOH groups attached to their surfaces. The results of the MD simulations show how an increase of the number of carboxylic groups on the CNT surface leads to a decrease on the Young moduli of the CNTs. The decrease of MWCNT Young’s modulus is found to be lower than in the case of SWCNT.

► Molecular dynamics was used to calculate elastic properties of functionalized CNTs.
► VdW repulsive interactions may limit functionalization with COOH beyond 25%.
► Elastic properties were found to decrease as degree of functionalization increases.
► Young Modulus is less affected by functionalization as the number of walls increases.