Investigation of the vibrational density of states of sodium carboxymethyl starch glass via terahertz time-domain spectroscopy.
Spectrochim Acta A Mol Biomol Spectrosc
; 266: 120414, 2022 Feb 05.
Article
in En
| MEDLINE
| ID: mdl-34619511
ABSTRACT
We investigated the vibrational density of states of sodium carboxymethyl starch (CM-starch) by terahertz (THz) time-domain spectroscopy. The CM-starch showed a broad peak at â¼3 THz. The structure of the peak was similar to those corresponding to glucose-based polymer glasses possessing hydrogen bonds. The boson peak (BP) appeared at 1.16 THz at the lowest temperature and disappeared because of the existence of excess wing at higher temperatures. However, based on our novel BP frequency determination method using the inflection point of the extinction coefficient, the BP frequency showed almost no dependence on temperature. Further, the chain length dependence of the BP frequency of the glucose-based glasses showed that the BP frequency of the polymer glass was slightly lower than that of the monomer glass. The power law behaviour of the absorption coefficient suggested the existence of fractons, and the fractal dimension was estimated to be 2.33.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Terahertz Spectroscopy
Language:
En
Journal:
Spectrochim Acta A Mol Biomol Spectrosc
Journal subject:
BIOLOGIA MOLECULAR
Year:
2022
Document type:
Article
Affiliation country:
Japan