Synergistic Formation of Radicals by Irradiation with Both Vacuum   Ultraviolet and Atomic Hydrogen: A Real-Time In Situ Electron Spin Resonance   Study
  We report on the surface modification of polytetrafluoroethylene (PTFE) as an example of soft- and bio-materials that occur under plasma discharge by kinetics analysis of radical formation using in situ real-time electron spin resonance (ESR) measurements. During irradiation with hydrogen plasma, simultaneous measurements of the gas-phase ESR signals of atomic hydrogen and the carbon dangling bond (C-DB) on PTFE were performed. Dynamic changes of the C-DB density were observed in real time, where the rate of density change was accelerated during initial irradiation and then became constant over time. It is noteworthy that C-DBs were formed synergistically by irradiation with both vacuum ultraviolet (VUV) and atomic hydrogen. The in situ real-time ESR technique is useful to elucidate synergistic roles during plasma surface modification. 
Kenji Ishikawa, Naoya Sumi, Akihiko Kono, Hideo Horibe, Keigo Takeda,   Hiroki Kondo, Makoto Sekine, and Masaru Hori
physics.chem-ph physics.bio-ph q-bio.QM