Analysis of effect of ion irradiation to liquid surface on water molecule kinetics by classical molecular dynamics simulation

Abstract

We analyzed the physical behavior of water molecules to assess the effect of ion bombardment from atmospheric-pressure plasma to a liquid surface by classical molecular dynamics simulation. As the incident ions, O+ was considered. The number of sputtered water molecules, liquid temperature, and ion penetration depth in liquid were investigated after O+ ions with kinetic energies of 10 and 100 eV impinged on the liquid surface. The average numbers of sputtered water molecules by ion impact were 0.5 at 10 eV and 7.0 at 100 eV. The sputtering of water molecules depended on the ion penetration depth and near-surface liquid temperature. The sputtering dynamics was discussed in detail. In addition, we presented the effect of an impinging ion on a liquid surface under an external electric field. The result shows that the number of sputtered water molecules increases with increasing electric field strength, which affects the water molecule orientation.