Energetics, timescales, and chemistry of low energy molecular ion-organic surface collisions

Several basic topics are presented here that are related to the modificatio n of organic surfaces by 10-100 eV molecular ions. First, experimental resu lts are presented for energy transfer for Si(CD3)(3)(+) and m/z 190-713 pep tide ions scattered off hexanethiolate self-assembled monolayers adsorbed o n Au(lll). Next, experimental and computer simulation results are presented on the dissociation timescales of these same ion-surface pairs. Finally, t he surface chemical modification of polystyrene polymer surfaces by CF3+ an d C3F5+ ions is analyzed by X-ray photoelectron spectroscopy. These results combine to demonstrate that low energy molecular ion-organic surface modif ication is highly surface selective, transfers a large fraction of the inci dent ion energy to the uppermost layer of the surface, can present unique r eactive species to the surface, and can transfer to the surface a portion o f the ion's chemical functionality. (C) 1999 Elsevier Science B.V. All righ ts reserved.