TY - JOUR
T1 - Heavy ion beam induced phenomena in polytetrafluoroethylene
AU - Oshima, Akihiro
AU - Murata, Katsuyoshi
AU - Oka, Toshitaka
AU - Miyoshi, Nozomi
AU - Matsuura, Akio
AU - Kudo, Hisaaki
AU - Murakami, Takeshi
AU - Katoh, Etsuko
AU - Washio, Masakazu
AU - Hama, Yoshimasa
N1 - Funding Information:
The authors acknowledge staffs of HIMAC operation division and staffs of accelerator engineering company for the experiments of high-energy ion beam irradiation. This study was supported by research project with heavy ions at NIRS-HIMAC. This work is performed by the project of RISE, Waseda University “the manufacturing of high functional fluorinated-polymer materials and its application” we would like to acknowledge the parties concerned.
PY - 2007/12
Y1 - 2007/12
N2 - This paper describes the results on thermal and chemical analysis of polytetrafluoroethylene (PTFE) film stack after high-energy heavy ion beam irradiation under atmospheric fields at room temperature. After high-energy C6+ ion beam irradiation, the PTFE film stack was separated one by one, and then the various measurements such as differential scanning calorimetric (DSC) analysis and solid-state 19F magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy were performed to get information of the chemical reaction and structural change at the localized positions. By ion beam irradiation for PTFE at room temperature, it is suggested that the abnormal phenomena due to the change of morphology could be observed by DSC analysis. In the solid-state 19F-MAS-NMR spectroscopy of ion irradiated PTFE film including Bragg peak region, several new signals were observed besides the intense peak of -CF2- at -124 ppm. The detected new signals in ion irradiated PTFE should be due to the changed chemical structures. The signals, which are assigned, to the tertiary carbon group with branching site (Y-type crosslinking site), perfluoro-propylene site and chain end methyl site were directly detected, though it was under the oxidation condition. Thus, although it was under the oxidation condition, the branching or crosslinking reaction was taken place with the chain scission in the matrix. Moreover, the branched chain length would become short, compared with EB-crosslinked PTFE. Hence, it could be suggested that the irradiation of heavy ion beam induced large amounts of intermediate species, compared with EB or γ-ray irradiation, and then, those would be reacted with each other in the localized area. Especially, in region of the Bragg peak, the ion beam induced more large amounts of intermediate species than in the other region.
AB - This paper describes the results on thermal and chemical analysis of polytetrafluoroethylene (PTFE) film stack after high-energy heavy ion beam irradiation under atmospheric fields at room temperature. After high-energy C6+ ion beam irradiation, the PTFE film stack was separated one by one, and then the various measurements such as differential scanning calorimetric (DSC) analysis and solid-state 19F magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy were performed to get information of the chemical reaction and structural change at the localized positions. By ion beam irradiation for PTFE at room temperature, it is suggested that the abnormal phenomena due to the change of morphology could be observed by DSC analysis. In the solid-state 19F-MAS-NMR spectroscopy of ion irradiated PTFE film including Bragg peak region, several new signals were observed besides the intense peak of -CF2- at -124 ppm. The detected new signals in ion irradiated PTFE should be due to the changed chemical structures. The signals, which are assigned, to the tertiary carbon group with branching site (Y-type crosslinking site), perfluoro-propylene site and chain end methyl site were directly detected, though it was under the oxidation condition. Thus, although it was under the oxidation condition, the branching or crosslinking reaction was taken place with the chain scission in the matrix. Moreover, the branched chain length would become short, compared with EB-crosslinked PTFE. Hence, it could be suggested that the irradiation of heavy ion beam induced large amounts of intermediate species, compared with EB or γ-ray irradiation, and then, those would be reacted with each other in the localized area. Especially, in region of the Bragg peak, the ion beam induced more large amounts of intermediate species than in the other region.
KW - Bragg peak
KW - C ion beam
KW - DSC
KW - F-MAS-NMR
KW - LET
KW - PTFE
KW - Tertiary carbon
UR - http://www.scopus.com/inward/record.url?scp=36048951377&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=36048951377&partnerID=8YFLogxK
U2 - 10.1016/j.nimb.2007.08.072
DO - 10.1016/j.nimb.2007.08.072
M3 - Article
AN - SCOPUS:36048951377
VL - 265
SP - 314
EP - 319
JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
SN - 0168-583X
IS - 1
ER -