Ions, osmolytes, and polymers at aqueous interfaces : insights from molecular theory and simulations

Abstract

We present an extensive quantitative analysis of the pair level interactions between monovalent ions at a water vapor-liquid interface. Our results highlight the sensitivity of the strength of water-mediated interactions in the interfacial environment, and suggest that these interactions may play an even more important role at the interface compared to that in bulk water. The thermodynamic driving forces that govern such interactions and their role in interface-mediated self-assembly (of peptides, ionic surfactants, proteins, and other macromolecules) is also discussed. Extensions of this work to understand the structure, dynamics and assembly of model polymer molecules at hydrophobic surfaces is also presented. The physical picture developed herein combined with the recent results on how interfaces affect the strength of hydrophobic interactions form key elements of a framework for understanding and manipulating self-assembly in interfacial environments.