Why direct or reversed hofmeister series? interplay of hydration, non-electrostatic potentials, and ion size

Parsons, D.F.ORCID: 0000-0002-3956-6031, Boström, M., Maceina, T.J., Salis, A. and Ninham, B.W. (2010) Why direct or reversed hofmeister series? interplay of hydration, non-electrostatic potentials, and ion size. Langmuir, 26 (5). pp. 3323-3328.

Abstract

A modified Poisson-Boltzmann analysis is made of the double layer interaction between two silica surfaces and two alumina surfaces in chloride electrolyte. The analysis incorporates nonelectrostatic ion-surface dispersion interactions based on ab initio ionic excess polarizabilities with finite ion sizes. A hydration model for the tightly held hydration shell of kosmotropic ions is introduced. A direct Hofmeister series (K > Na > Li) is found at the silica surface while the reversed series (Li > Na > K) is found at alumina, bringing theory in line with experiment for the first time. Calculations with unhydrated ions also suggest that surface-induced dehydration may be occurring at the alumina surface.

Item Type:	Journal Article
Publisher:	American Chemical Society
Copyright:	© 2009 American Chemical Society
URI:	http://researchrepository.murdoch.edu.au/id/eprint/27275

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