2024-03-29T06:32:34Z
https://tsukuba.repo.nii.ac.jp/oai
oai:tsukuba.repo.nii.ac.jp:00045963
2022-04-27T09:17:42Z
117:148
117:1940
3:62:5601:6465
Boson peak dynamics of natural polymer starch investigated by terahertz time-domain spectroscopy and low-frequency Raman scattering
森, 龍也
小島, 誠治
Terao, Wakana
Mori, Tatsuya
Fujii, Yasuhiro
Koreeda, Akitoshi
Kabeya, Mikitoshi
Kojima, Seiji
© 2018.
This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
Terahertz time-domain spectroscopy and low-frequency Raman scattering were performed on the natural polymer starch to investigate the boson peak (BP) dynamics. In the infrared spectrum, the BP was observed at 0.99 THz at the lowest temperature. Compared to the result from a previous study for vitreous glucose, both the frequency of the BP and absorption coefficient show lower values than those of the vitreous glucose. These behaviors originate from the longer correlation length of the medium-range order and lower concentration of hydroxyl groups in the starch. In the Raman spectrum, the BP was observed at 1.1 THz at room temperature, although the BP was not observed around room temperature due to the excess wing of the fast relaxation modes in the infrared spectrum. The temperature dependence of ε″(ν) during the heating process and cooling process shows a hysteresis below 230 K. During the heating process, kinks were observed at 140 K and 230 K. These kinks are attributed to the β-relaxation and the βwet-relaxation, respectively.
Elsevier
2018-03
eng
journal article
http://hdl.handle.net/2241/00151241
https://tsukuba.repo.nii.ac.jp/records/45963
29216599
10.1016/j.saa.2017.11.051
13861425
AA1103958X
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy
192
446
450
https://tsukuba.repo.nii.ac.jp/record/45963/files/SAPA_192.pdf
application/pdf
589.2 kB
2020-04-01