Beyond the first hydration shell: dielectric study of LiCl aqueous solution

Abstract

The dielectric constant for lithium chloride (LiCl) in aqueous solution with the entire concentration has been determined in the frequency range 0.5 GHz–50GHz at 298 K by dielectric relaxation spectroscopy (DRS). The system behaviour is described according to the Cole–Cole and two Debye-type relaxation functions whose evolution with composition is analysed. Combining the Cole–Cole and two Debye-type relaxation functions, the results of the dielectric properties of aqueous LiCl solution are presented and discussed. The maximum number of water molecules perturbed by ions in the hydration shell decays with its concentration. Using the extended Froehlich theory, it is concluded that the water structure is perturbed by ions beyond the first hydration shell in LiCl aqueous solution system.

Keywords:

• Dielectric constant
• Cole–Cole and two Debye-type
• hydration shell

Acknowledgement

We are very grateful that Prof. Yuri Feldman and Prof. Evgeniya Levy gave us heuristic idea.

Additional information

Funding

This project was supported by the National Science Foundation of China [Grant NO 61102044]. We would like to thank Agilent Cheng Du Ltd. for the loan of Vector Network Analyzer Agilent N5227A PNA-X.