Confinement of CO2 inside carbon nanotubes

We propose a preliminary study based on molecular dynamics calculations to investigate the adsorption of pure CO2 on flexible single-walled carbon nanotubes (SWCNTs) of different sizes. The adsorption capacities of SWCNTs were simulated and the effect of chirality and diameter of SWCNTs was assessed, to check them as sizable carbon structured materials suitable for CO2 confinement and storage. The potential energy surfaces, describing the intermolecular interactions involving CO2-SWCNT and CO2-CO2 pairs, have been described specifically by adopting the improved lennard jones model potential. The intramolecular interactions within the SWCNT were considered explicitly since they are responsible for out-of-plane movements of carbon atoms and the flexibility of nanotubes. These well-formulated potentials are well capable of defining CO2 confinement through physisorption and guarantee a quantitative description and realistic results for the dynamics of the interactions. The flexible SWCNTs can adsorb up to 35 wt% at 273 K, a property that makes them potentially versatile materials competitive with other carbon-derived adsorbents to cope with CO2 gas emission.