Modeling Ion-Specific Correlations in Bulk and Confinement
Dr. Immanuel Kalcher
Physics Department
Technical University Munich
Germany
ABSTRACT
Ion-specific effects are ubiquitous in nature and have relevance in colloidal
science, electrochemistry, and geological and biological physics. The molecular
origin and the coarse-grained modeling of these effects are still widely unexplored.
In this talk we attempt to give more molecular insight into the individual
correlations in aqueous electrolyte systems which give rise to the ion-specific
behavior in bulk (e.g., the osmotic pressure) or in confinement (e.g., between
colloidal or biological surfaces). Particularly, we present a nonlocal
Poisson-Boltzmann theory, based on classical density functional theory,
which captures and rationalizes ion-specific excluded-volume correlations
(the 'size effect') in dense electrolytes and may help understanding the
restabilization of proteins, clays, and colloids at high salt concentrations.
The importance of electrostatic correlations at low dielectric constants is
briefly discussed.
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