Elastic Properties of Functionalized Carbon Nanotubes

TL;DR

This study investigates how covalent functionalization with various organic molecules affects the elastic properties of single wall carbon nanotubes, revealing a decrease in elastic moduli with increased functionalization density.

Contribution

It provides first principles calculations showing the impact of specific organic functional groups on CNT elasticity, highlighting the potential for composite reinforcement.

Findings

Elastic moduli decrease with higher functionalization density.

-CH2 functionalization causes a 30% reduction in Young's modulus.

Functionalized CNTs remain suitable for reinforcement applications.

Abstract

We study the effects of covalent functionalization of single wall carbon nanotubes (CNT) on their elastic properties. We consider simple organic molecules -NH, -NH2, -CH2, -CH3, -OH attached to CNTs' surface at various densities. The studies are based on the first principles calculations in the framework of density functional theory. We have determined the changes in the geometry and the elastic moduli of the functionalized CNTs as a function of the density of adsorbed molecules. It turns out that elastic moduli diminish with increasing concentration of adsorbands, however, the functionalized CNTs remain strong enough to be suitable for reinforcement of composites. The strongest effect is observed for CNTs functionalized with -CH2 radical, where the Young's modulus of the functionalized system is by 30% smaller than in the pristine CNTs.