Communication: Mean-field theory of water-water correlations in electrolyte solutions

• DOI: 10.1063/1.4983221
• Publication Date: 2017-05-10T14:43:33Z
• Authors: David M. Wilkins; David E. Manolopo...; Sylvie Roke; Michele Ceriotti
• Keywords: /dk/atira/pure/subjectarea/asjc/1600/1606; Debye-Hückel Theory; Statistical Mechanics (cond-mat.stat-mech); Water; FOS: Physical sciences; Nonlinear Light Scattering; 02 engineering and technology; Condensed Matter - Soft Condensed Matter; Molecular Dynamics; 540; 530; 3. Good health; name=General Physics and Astronomy; Soft Condensed Matter (cond-mat.soft); /dk/atira/pure/subjectarea/asjc/3100/3100; 0210 nano-technology; Condensed Matter - Statistical Mechanics; name=Physical and Theoretical Chemistry

Long-range ion induced water-water correlations were recently observed in femtosecond elastic second harmonic scattering experiments of electrolyte solutions. To further the qualitative understanding of these correlations, we derive an analytical expression that quantifies ion induced dipole-dipole correlations in a non-interacting gas of dipoles. This model is a logical extension of the Debye-Hückel theory that can be used to qualitatively understand how the combined electric field of the ions induces correlations in the orientational distributions of the water molecules in an aqueous solution. The model agrees with the results from molecular dynamics simulations and provides an important starting point for further theoretical work.