Theoretical studies of hyperthermal O( ³P) collisions with hydrocarbon self-assembled monolayers

A dynamics study of inelastic and reactive scattering processes in collisions of hyperthermal (5 eV) O( ³P) atoms with a hydrocarbon self-assembled monolayer (SAM) was analyzed. Molecular dynamics simulations were carried out using a quantum mechanics/molecular mechanics (QM/MM) interaction potential. It was shown that C-C breakage mechanism provides a pathway for significant surface mass loss in single reactive events whereas the O addition-H elimination channel leads to surface oxidation. To gain insight on polymer erosion in low Earth orbit conditions and on fundamentals of inelastic and reactive hyperthermal gas-surface interactions, reaction probabilities, product energy and angular distributions were examined.