Work

Glasslike behavior in aqueous electrolyte solutions

Year: 2008

Type: article

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.

Source: The Journal of Chemical Physics

DOI: 10.1063/1.2906132

Authors: David A. Turton, Johannes Hunger, Glenn Hefter, Richard Buchner, Klaas Wynne

Institutions: University of Strathclyde, University of Regensburg, Murdoch University

Language: English

Topic: Material Dynamics and Properties

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funder: Engineering and Physical Sciences Research Council

Award: G7139499687