Ionic conductivity on a wetting surface.
Recent experiments measuring the electrical conductivity of DNA molecules highlight the need for a theoretical model of ion transport along a charged surface. Here we present a simple theory based on the idea of unbinding of ion pairs. The strong humidity dependence of conductivity is explained by the decrease in the electrostatic self-energy of a separated pair when a layer of water (with high dielectric constant) is adsorbed to the surface. We compare our prediction for conductivity to experiment and discuss the limits of its applicability.
Skinner
Brian
B
Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Loth
M S
MS
Shklovksii
B I
BI
D000327:Adsorption; D004553:Electric Conductivity; D007477:Ions / Q000737:chemistry; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D007477:Ions; D014867:Water