Abstract
Optical absorption spectra and photoluminescence spectra were obtained for eight kinds of polyolefin sheet samples using photons in a range from visible to vacuum ultraviolet. Almost all samples were found to exhibit an absorption peak at around 6.5 eV and a luminescence band at around 4.3 eV. The luminescence was found to be induced by the absorption. Furthermore, it was found that successive absorption of ultraviolet photons weakened the luminescence intensity. It is assumed from these results that α ,β -unsaturated carbonyls are luminous and that the carbonyls are decomposed through the Norrish type II reaction by absorbing ultraviolet photons. Quantum chemical calculations were carried out using polyethylene models with and without an unsaturated carbonyl to verify the above-mentioned assumption. As a result, the model with an unsaturated carbonyl was found to have localized electronic states in the forbidden band. One of the differential energies between the states is close to the photon energy, by which the luminescence is induced. The bond length of a double bond, which is next to the carbonyl, was found to be longer at the excited singlet state than at the ground state. These results obtained by computation support the above-mentioned assumption of the luminescence center and its decomposition.
| Original language | English |
|---|---|
| Pages (from-to) | 760-766 |
| Number of pages | 7 |
| Journal | IEEJ Transactions on Fundamentals and Materials |
| Volume | 132 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 2012 |
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Keywords
- Computational chemistry
- Optical absorption
- Photoluminescence
- Polyolefin
- Quantum chemical calculation
ASJC Scopus subject areas
- Electrical and Electronic Engineering
Cite this
Optical characterization and computational chemical evaluation of electronic localized states in polyolefin. / Arai, Tomoyuki; Hosobuchi, Masashi; Fuse, Norikazu; Takeda, Kyozaburo; Ohki, Yoshimichi.
In: IEEJ Transactions on Fundamentals and Materials, Vol. 132, No. 9, 2012, p. 760-766.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Optical characterization and computational chemical evaluation of electronic localized states in polyolefin
AU - Arai, Tomoyuki
AU - Hosobuchi, Masashi
AU - Fuse, Norikazu
AU - Takeda, Kyozaburo
AU - Ohki, Yoshimichi
PY - 2012
Y1 - 2012
N2 - Optical absorption spectra and photoluminescence spectra were obtained for eight kinds of polyolefin sheet samples using photons in a range from visible to vacuum ultraviolet. Almost all samples were found to exhibit an absorption peak at around 6.5 eV and a luminescence band at around 4.3 eV. The luminescence was found to be induced by the absorption. Furthermore, it was found that successive absorption of ultraviolet photons weakened the luminescence intensity. It is assumed from these results that α ,β -unsaturated carbonyls are luminous and that the carbonyls are decomposed through the Norrish type II reaction by absorbing ultraviolet photons. Quantum chemical calculations were carried out using polyethylene models with and without an unsaturated carbonyl to verify the above-mentioned assumption. As a result, the model with an unsaturated carbonyl was found to have localized electronic states in the forbidden band. One of the differential energies between the states is close to the photon energy, by which the luminescence is induced. The bond length of a double bond, which is next to the carbonyl, was found to be longer at the excited singlet state than at the ground state. These results obtained by computation support the above-mentioned assumption of the luminescence center and its decomposition.
AB - Optical absorption spectra and photoluminescence spectra were obtained for eight kinds of polyolefin sheet samples using photons in a range from visible to vacuum ultraviolet. Almost all samples were found to exhibit an absorption peak at around 6.5 eV and a luminescence band at around 4.3 eV. The luminescence was found to be induced by the absorption. Furthermore, it was found that successive absorption of ultraviolet photons weakened the luminescence intensity. It is assumed from these results that α ,β -unsaturated carbonyls are luminous and that the carbonyls are decomposed through the Norrish type II reaction by absorbing ultraviolet photons. Quantum chemical calculations were carried out using polyethylene models with and without an unsaturated carbonyl to verify the above-mentioned assumption. As a result, the model with an unsaturated carbonyl was found to have localized electronic states in the forbidden band. One of the differential energies between the states is close to the photon energy, by which the luminescence is induced. The bond length of a double bond, which is next to the carbonyl, was found to be longer at the excited singlet state than at the ground state. These results obtained by computation support the above-mentioned assumption of the luminescence center and its decomposition.
KW - Computational chemistry
KW - Optical absorption
KW - Photoluminescence
KW - Polyolefin
KW - Quantum chemical calculation
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UR - http://www.scopus.com/inward/citedby.url?scp=84867093331&partnerID=8YFLogxK
U2 - 10.1541/ieejfms.132.760
DO - 10.1541/ieejfms.132.760
M3 - Article
VL - 132
SP - 760
EP - 766
JO - IEEJ Transactions on Fundamentals and Materials
JF - IEEJ Transactions on Fundamentals and Materials
SN - 0385-4205
IS - 9
ER -