Chemical Dynamics Simulations of CO2Scattering off a Fluorinated Self-Assembled Monolayer Surface

Abstract

Chemical dynamics simulations at collision energies of 3.0, 10.6, and 20.0 kcal/mol were performed to study energy transfer in perpendicular (θi = 0°) collisions of carbon dioxide with a perfluorinated octanethiol self-assembled monolayer (F-SAM) surface. An accurate carbon dioxide + F-SAM intermolecular potential was developed from ab initio calculations extrapolated to the complete basis set limit. Three types of collision events are observed in the trajectories: direct scattering, physisorption on the top of the surface, and penetration of the surface. Energy transfer to carbon dioxide rotation and the final translational energy of carbon dioxide are both analyzed for each of these trajectory types. Penetration leads to near complete thermal accommodation with the F-SAM, whereas accommodation is not reached for either the direct or physisorption trajectories. The distributions of the translational energy and rotational angular momentum, P(Ef) and P(J), of the scattered CO2 molecules and for the differ...