Spatial variation of permittivity of an electrolyte solution in contact with a charged metal surface: a mini review.
Comput Methods Biomech Biomed Engin
; 16(5): 463-80, 2013.
Article
in En
| MEDLINE
| ID: mdl-22263808
ABSTRACT
Contact between a charged metal surface and an electrolyte implies a particular ion distribution near the charged surface, i.e. the electrical double layer. In this mini review, different mean-field models of relative (effective) permittivity are described within a simple lattice model, where the orientational ordering of water dipoles in the saturation regime is taken into account. The Langevin-Poisson-Boltzmann (LPB) model of spatial variation of the relative permittivity for point-like ions is described and compared to a more general Langevin-Bikerman (LB) model of spatial variation of permittivity for finite-sized ions. The Bikerman model and the Poisson-Boltzmann model are derived as limiting cases. It is shown that near the charged surface, the relative permittivity decreases due to depletion of water molecules (volume-excluded effect) and orientational ordering of water dipoles (saturation effect). At the end, the LPB and LB models are generalised by also taking into account the cavity field.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Electrolytes
/
Metals
/
Models, Chemical
Language:
En
Journal:
Comput Methods Biomech Biomed Engin
Journal subject:
ENGENHARIA BIOMEDICA
/
FISIOLOGIA
Year:
2013
Document type:
Article
Affiliation country:
Slovenia