Theoretical study of ion desorption from poly-(methyl methacrylate) and poly-(isopropenyl acetate) thin films through core excitation

Takahashi Osamu

Tabayashi Kiyohiko

Wada Shin-ichi

Sumii Ryouhei

Tanaka Kenichiro

Odelius Michael

Pettersson Lars G. M.

Journal of Chemical Physics

Site-specific chemical reactions following core excitation of poly-(methyl methacrylate) (PMMA) and poly-(isopropenyl acetate) (PiPAc) thin films were investigated. New x-ray absorption spectra of PMMAand PiPAc at the C and O K edges and theoretical spectra within the framework of density functional theory using model molecules were reported, and some new peak assignments were proposed for these spectra. Core-hole excited state molecular dynamics simulations were performed to discuss dissociation dynamics for the target systems, and some specific reaction mechanisms were discussed and explained theoretically; for example, the amount of CH3 ion fragments for PMMA was enhanced at the C and O K edges through the existence of the repulsive σ*(O–CH3) excited state.

polymer films

desorption

surface chemistry

X-ray absorption spectra

density functional theory

excited states

molecular dynamics method

dissociation

eng

American Institute of Physics

Copyright (c) 2006 American Institute of Physics.

[ISSN] 0021-9606

[DOI] 10.1063/1.2176605

[NCID] AA00694991

[DOI] http://dx.doi.org/10.1063/1.2176605