Glasslike behavior in aqueous electrolyte solutions

Turton, D.A., Hunger, J., Hefter, G., Buchner, R. and Wynne, K. (2008) Glasslike behavior in aqueous electrolyte solutions. Journal of Chemical Physics, 128(16), p. 161102. (doi:10.1063/1.2906132)

Full text not currently available from Enlighten.

Abstract

When salts are added to water, generally the viscosity increases, suggesting that 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 enhancement or breakdown of the hydrogen-bond network. Here, we report optical Kerr effect and dielectric relaxation 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.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Wynne, Professor Klaas
Authors: Turton, D.A., Hunger, J., Hefter, G., Buchner, R., and Wynne, K.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:Journal of Chemical Physics
ISSN:0021-9606
Published Online:24 April 2008

University Staff: Request a correction | Enlighten Editors: Update this record