Effects of concentration on the microwave dielectric spectra of aqueous urea solutions
| Autor: | A. Yu. Zasetsky, V. S. Dunyashev, A. K. Lyashchenko |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Aqueous solution
010304 chemical physics Relaxation (NMR) Analytical chemistry 010402 general chemistry 01 natural sciences Spectral line 0104 chemical sciences chemistry.chemical_compound symbols.namesake Dielectric spectrum chemistry 0103 physical sciences Urea symbols Molecule Physical and Theoretical Chemistry Microwave Debye |
| Zdroj: | Russian Journal of Physical Chemistry A. 91:887-893 |
| ISSN: | 1531-863X 0036-0244 |
| DOI: | 10.1134/s0036024417050168 |
| Popis: | Several models of relaxation for the dielectric spectra of aqueous urea solutions in the microwave region are compared. The spectra are shown to contain two main Debye components arising from the rotational motions of urea and water molecules. Two essentially different concentration regions in urea solutions are identified. The first is characterized by a small increase in the mobility of water molecules (τ1 = 7.8 ps) and the existence of hydrated urea molecules (τ2 = 19 ps). Due to the aggregation of urea molecules, the relaxation times for the latter process grow considerably in highly concentrated solutions. At the same time, faster molecular motions (τ3 = 6 ps) are observed for water molecules. |
| Databáze: | OpenAIRE |
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