Chemometric study of kosmotropic and chaotropic ion properties related to Hofmeister effects

Abstract

The ion specificity is ubiquitous in biological and colloidal phenomena. In this study, the Hofmeister effects have been observed in binding of univalent cations with the surfactant dimers. Chemometric analysis has also revealed that the ion specificity observed is mainly related to the effect of ions on the water structure, ie, to their kosmotropic and chaotropic properties. These ion properties, generally characteristic of aqueous solutions, are in accordance with the results of the principal component analysis (PCA) and cluster analysis (CA) used for the processing of mass spectrometric data obtained in vacuum, ie, in the medium drastically different then water. Such an application of the chemometric methods has not been presented so far.

The structure-giving role of Rb+ ions for water–ice nanoislands supported on Cu(111)

“…It is barely altered during solvation, to 0.86 e À at 0.16 ML Cs + with 6 D 2 O molecules per Cs + . 59 In this article, we investigate the influence of the solvation of rubidium (Rb + ), a large ion with structure-breaking properties in the liquid phase 60 on the area, apparent height, and fractal dimension of comparable water islands on Cu(111). Similar to the recently calculated Cs + ions, a charge close to 1 e À is expected at the low coverages employed here.…”