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Characteristic terahertz absorption spectra of paramylon and paramylon-ester compounds
Junlan Zhong1, Tatsuya Mori2, Takanari Kashiwagi2
1Graduate School of Life and Environment Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
|September 4, 2020
Summary
Paramylon and its esters exhibit unique terahertz absorption peaks, enabling their detection and identification. These spectral fingerprints are independent of molecular size but correlate with the degree of substitution in paramylon-esters.
Area of Science:
- Biophysics
- Materials Science
- Spectroscopy
Background:
- Paramylon is a glucose-based polysaccharide with a unique three-strand helical structure.
- Paramylon-esters are derivatives with enhanced properties for thermoplastic applications.
- Understanding the spectral properties of paramylon and its derivatives is crucial for their characterization.
Purpose of the Study:
- To measure and compare the terahertz absorption spectra of paramylon and paramylon-esters.
- To identify unique spectral features (fingerprints) for these molecules.
- To establish a correlation between spectral properties and molecular characteristics like degree of substitution.
Main Methods:
- Terahertz (THz) absorption spectroscopy (0.3-8.0 THz range).
- Measurement of absorption coefficient α(ν) and absorbance spectra.
- Comparison with glucose and cellulose spectra.
- Analysis of spectral features in relation to molecular weight and degree of substitution (DS).
Main Results:
- Paramylon and paramylon-esters show distinct fingerprint absorption peaks in the THz range.
- Absorption spectra are independent of paramylon molecular weight.
- A strong linear correlation (R² > 0.99) was found between THz peak intensity and the DS of paramylon-esters.
Conclusions:
- THz spectroscopy can effectively identify and characterize paramylon and its esters.
- The established correlation provides a method for quantifying the DS of paramylon-esters.
- These findings facilitate the development and application of novel paramylon-ester materials.
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