Glasslike Behavior in Aqueous Electrolyte Solutions
Abstract
When salts are added to water, the viscosity generally increases suggesting the ions increase the strength of the water's hydrogen-bond network. However, infrared pump-probe measurements on electrolyte solutions have found that ions have no influence on the rotational dynamics of water molecules implying no enhance-ment or breakdown of the hydrogen-bond network. Here we report optical Kerr-effect and dielectric relaxa-tion spectroscopic measurements, which have enabled us to separate the effects of rotational and transitional motions of the water molecules. These data show that electrolyte solutions behave like a supercooled liquid approaching a glass transition in which rotational and translational molecular motions are decoupled. It is now possible to understand previously conflicting viscosity data, nuclear magnetic resonance relaxation, and ultrafast infrared spectroscopy in a single unified picture.
Cite
@article{arxiv.0904.0717,
title = {Glasslike Behavior in Aqueous Electrolyte Solutions},
author = {David A. Turton and Johannes Hunger and Glenn Hefter and Richard Buchner and Klaas Wynne},
journal= {arXiv preprint arXiv:0904.0717},
year = {2009}
}