The Electrochemical Surface Potential Due to Classical Point Charge Models Drives Anion Adsorption to the Air-Water Interface

Abstract

We demonstrate that the driving forces for ion adsorption to the air-water interface for point charge models results from both cavitation and a term that is of the form of a negative electrochemical surface potential. We carefully characterize the role of the free energy due to the electrochemical surface potential computed from simple empirical models and its role in ionic adsorption within the context of dielectric continuum theory. Our research suggests that the electrochemical surface potential due to point charge models provides anions with a significant driving force to the air-water interface. This is contrary to the results of ab initio simulations that indicate that the average electrostatic surface potential should favor the desorption of anions at the air-water interface. The results have profound implications for the studies of ionic distributions in the vicinity of hydrophobic surfaces and proteins.

References in corpus (1)

• Surface tensions, surface potentials and the Hofmeister series of electrolyte solutions

Cited by in corpus (10)

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• Hydrophobicity Scaling of Aqueous Interfaces by an Electrostatic Mapping
• Interfacial ion solvation: Obtaining the thermodynamic limit from molecular simulations
• Assessing long-range contributions to the charge asymmetry of ion adsorption at the air-water interface
• The Influence of Distant Boundaries on the Solvation of Charged Particles
• Mobility of nanometer-size solutes in water driven by electric field
• Adsorption of cationic polyions to a hydrophobic surface in the presence of Hofmeister salts