Hyperthermal atomic oxygen and argon modification of polymer surfaces investigated by molecular dynamics simulations

The deposition of reactive and unreactive particles on polymer surfaces at hyperthermal incident energies is investigated using classical molecular dynamics simulations. The forces are calculated with the second-generation reactive empirical bond-order potential with modified parameters for C,H,O interactions. Three prototypical polymers, polyethylene (PE), polypropylene (PP) and polystyrene (PS), are modified by atomic oxygen and argon that are deposited with kinetic energies of 25, 50 and 100 eV. The non-reactive argon is predicted to primarily break carbon-carbon bonds and remove hydrogen as a secondary process, while the reactive oxygen is more efficient at removing hydrogen during new bond formation with the polymer. The PE and PP are found to have similar responses to hyperthermal argon and oxygen deposition, while PS is found to be the most susceptible to oxygen modification.