Complex dielectric permittivity and relaxation parameters of concentrated aqueous electrolyte solutions in millimeter and centimeter wavelength ranges

✍ Scribed by A.K. Lyashchenko; A.Yu. Zasetsky

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 699 KB
• Volume: 77
• Category: Article
• ISSN: 0167-7322
• DOI: 10.1016/s0167-7322(98)00068-3

✦ Synopsis

The complex dielectric permittivity of aqueous electrolyte solutions in a wide range of concentrations was comprehensively studied between 7 and 120 GHz. In the first concentration region, experimental data are described in terms of the Debye or Cole-Cole relaxation models. No resonance or relaxation processes other than the Debye rotational diffusion of water molecules occur in a high-frequency part of the millimeter wavelength range. Concentrated aqueous LiC1 and MgC12 solutions exhibit two separate regions of the complex permittivity dispersion with considerably different (5-10 times) relaxation times. Decomposition of the dielectric spectra in a wide frequency range points to the occurrence of two simple relaxation processes. It is assumed that they are dominated by relaxation of water molecules incorporated in hydration shells and in ion-water clusters, respectively. The lifetime of water molecules in the clusters is 12-18 ps.