Persson RAX. On the dielectric decrement of electrolyte solutions: a dressed-ion theory analysis.
Phys Chem Chem Phys 2018;
19:1982-1987. [PMID:
28009858 DOI:
10.1039/c6cp07515k]
[Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Based on the dressed-ion theory and a simple physical argument regarding the conductivity of the solution, we derive a relation between the ionic strength and dielectric constant of an electrolyte solution. At its simplest, this model gives the dielectric constant at low ionic strength I as εr(I) = εr(0)(1 + αI)-1, where α (the excess polarization) is directly related to the dressed-ion charge. One contribution to the origin of the dielectric decrement is thus seen to stem from the electrostatic screening of the ions in solution, with no solvent contributions necessary.
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