Collisions between CO, CO_2, H_2O and Ar ice nanoparticles compared by molecular dynamics simulation

Abstract

Molecular dynamics simulations are used to study collisions between amorphous ice nanoparticles consisting of CO, CO_2, Ar and H_2O. The collisions are always sticking for the nanoparticle size (radius of 20 nm) considered. At higher collision velocities, the merged clusters show strong plastic deformation and material mixing in the collision zone. Collision-induced heating influences the collision outcome. Partial melting of the merged cluster in the collision zone contributes to energy dissipation and deformation. Considerable differences exist—even at comparable collision conditions—between the ices studied here. The number of ejecta emitted during the collision follows the trend in triple-point temperatures and increases exponentially with the NP temperature.