Jump to main content
Jump to site search

Issue 16, 2007
Previous Article Next Article

Separable cooperative and localized translational motions of water confined by a chemically heterogeneous environment

Author affiliations

Abstract

We report quasi-elastic neutron scattering experiments at two resolutions that probe timescales of picoseconds to nanoseconds for the hydration dynamics of water, confined in a concentrated solution of N-acetyl-leucine-methylamide (NALMA) peptides in water over a temperature range of 248 K to 288 K. The two QENS resolutions used allow for a clean separation of two observable translational components, and ultimately two very different relaxation processes, that become evident when analyzed under a combination of the jump diffusion model and the relaxation cage model. The first translational motion is a localized β-relaxation process of the bound surface water, and exhibits an Arrhenius temperature dependence and a large activation energy of ∼8 kcal mol−1. The second non-Arrhenius translational component is a dynamical signature of the α-relaxation of more fluid water, exhibiting a glass transition temperature of ∼116 K when fit to the Volger Fulcher Tamman functional form. These peptide solutions provide a novel experimental system for examining confinement in order to understand the dynamical transition in bulk supercooled water by removing the unwanted interface of the confining material on water dynamics.

Graphical abstract: Separable cooperative and localized translational motions of water confined by a chemically heterogeneous environment

Back to tab navigation

Supplementary files

Article information


Submitted
22 Nov 2006
Accepted
15 Jan 2007
First published
06 Feb 2007

Phys. Chem. Chem. Phys., 2007,9, 1962-1971
Article type
Paper

Separable cooperative and localized translational motions of water confined by a chemically heterogeneous environment

C. Malardier-Jugroot and T. Head-Gordon, Phys. Chem. Chem. Phys., 2007, 9, 1962 DOI: 10.1039/B616997J

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

Search articles by author

Spotlight

Advertisements