Issue 26, 2013

Slow dynamics of water molecules in an aqueous solution of lithium chloride probed by neutron spin-echo

Abstract

Aqueous solutions of lithium chloride are uniquely similar to pure water in the parameters such as glass transition temperature, Tg, yet they could be supercooled without freezing down to below 200 K even in the bulk state. This provides advantageous opportunity to study low-temperature dynamics of water molecules in water-like environment in the bulk rather than nano-confined state. Using high-resolution neutron spin-echo data, we argue that the critical temperature, Tc, which is also common between lithium chloride aqueous solutions and pure water, is associated with the split of a secondary relaxation from the main structural relaxation on cooling down. Our results do not allow distinguishing between a well-defined separate secondary relaxation process and the “excess wing” scenario, in which the temperature dependence of the secondary relaxation follows the main relaxation. Importantly, however, in either of these scenarios the secondary relaxation is associated with density–density fluctuations, measurable in a neutron scattering experiment. Neutron scattering could be the only experimental technique with the capability of providing information on the spatial characteristics of the secondary relaxation through the dependence of the signal on the scattering momentum transfer. We propose a simple method for such analysis.

Graphical abstract: Slow dynamics of water molecules in an aqueous solution of lithium chloride probed by neutron spin-echo

Article information

Article type
Paper
Submitted
30 Mar 2013
Accepted
13 May 2013
First published
14 May 2013

Phys. Chem. Chem. Phys., 2013,15, 10732-10739

Slow dynamics of water molecules in an aqueous solution of lithium chloride probed by neutron spin-echo

E. Mamontov and M. Ohl, Phys. Chem. Chem. Phys., 2013, 15, 10732 DOI: 10.1039/C3CP51355F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements