Dielectric relaxation of collagen in aqueous solutions

Autor:	Yasaku Wada, Masanori Sakamoto, Shin'ichiro Umemura, Reinosuke Hayakawa
Rok vydání:	1979
Předmět:	chemistry.chemical_classification Aqueous solution Organic Chemistry Relaxation (NMR) Biophysics Analytical chemistry General Medicine Polymer Dielectric Biochemistry Biomaterials Dipole Nuclear magnetic resonance chemistry Ionization Side chain Reduced viscosity
Zdroj:	Biopolymers. 18:25-34
ISSN:	1097-0282 0006-3525
DOI:	10.1002/bip.1979.360180104
Popis:	The complex dielectric constant of collagen in aqueous solutions (polymer concentration, Cp = 0.02–0.2%) was measured at 10°C in the frequency range from 3 Hz to 30 kHz. The loss peak for Cp = 0.02% is located at 90 Hz and the dielectric relaxation time τD is estimated to be 1.8 ± 0.3 msec. The τD agrees well with the rotational relaxation time estimated from the reduced viscosity, and the relaxation is ascribed to the end-over-end rotation of the molecule. The Cp dependence of τD and the dielectric increment Δe are interpreted in terms of the aggregation of molecules. The dipole moment of a molecule, obtained from Δe at Cp = 0.02% and pH 6.5, is (5.2 ± 0.2) × 104D, which is explained by the asymmetrical distribution of the ionized side chains of the molecule.
Databáze:	OpenAIRE
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