AN OVERVIEW OF MICROWAVE DIELECTRIC SPECTROMETRY ON AQUEOUS MEDIUM

The dielectric relaxation research on aqueous solutions is summarised to determine the relative strengths and limits of various solution models. Inorganic and organic electrolytes, as well as low-molecular-weight organic molecules, are among the solutes. It is demonstrated that even relatively simple solutions have a wide range of impacts. The hydration hypothesis appears to be validated due to the preferential orientation of water molecules in the Coulombic field of tiny ions and also in clathrate-like structures around big ions for solutions of such solutes. A hydration model appears to be appropriate for the solution of primarily hydrophobic compounds. Consequently, hydrophilic molecules are included in a hydrogen-bonded network. Many situations make it difficult to differentiate between the contributions of the solute and solvent molecules to the dielectric spectrum. Using such combinations, it is much more difficult to distinguish distinct water locations that have been influenced differently. In this review, we explored dielectric relaxation spectroscopy as a contemporary area of interest in aqueous solution. The dielectric characteristics of liquids at microwave frequencies are summarised, and the underlying molecular mechanisms and techniques are described. The peculiar behaviour of aquatic systems is given special consideration in this review.