Theoretical description of ionic solutions using integral equation theory
(with W. Kunz)
Ions play an important role in many natural, biological, and technological processes. As a consequence, various experimental techniques are used to assess properties of ionic solutions. A theoretical description of these solutions can provide complementary information, and can be also used for predictions of their properties without the need to perform experiments.
We use the integral equation theory (namely the Ornstein-Zernike equation with the Hypernetted Chain closure relation) to obtain such models of ionic solutions.
Our study requires very close collaboration with specialists from other fields of (not only) physical chemistry. The development of reliable interaction potentials would not be possible without the methods of computational chemistry, namely molecular dynamics simulations and quantum mechanical calculations. The Poisson-Boltzmann equation can be used for modeling of the interfaces of ionic solutions and, therefore, provides interesting insights into the physics of the interfacial behavior of ions. It is also an important source of material for comparison with the integral equation theory. Finally, experiments (when available) provide essential data that can be used for benchmarking and validating theoretical findings.
Ion interactions with proteins - Na vs. K at protein interfaces
(with P. Jungwirth)
Our current project related to the interactions of ions with proteins focuses on the preferrential adsorption of sodium vs. potassium ions to the protein surfaces, that can be rationalized mainly by the stronger pairing of the former with the sidechain carboxylate groups of Asp and Glu aminoacids. This effect can be seen in simulations of proteins, peptides, isolated aminoacids, in quantum chemical calculations of model systems (formate, acetate), and also in experiment.
