Thomas Beck of the University of Cincinnati is supported by the Chemical Theory, Models and Computational Methods program in the Chemistry Division to carry out theoretical and computational studies of specific ion or Hofmeister effects in water and non-aqueous solvents. A range of theoretical tools, including free energy partitioning methods such as the quasichemical theory and the local molecular field theory, is being employed to explore specific ion solvation in complex environments. Three general problems are addressed: 1) computation of ion hydration free energies at the quantum mechanical level 2) detailed analysis of the Law of Matching Water Affinities by free energy partitioning and 3) fundamental studies of ion solvation in non-aqueous solvents such as ethylene carbonate and propylene carbonate with application to energy storage in lithium-ion batteries and supercapacitors. Both classical and high-level quantum methods are utilized in partitioning the interactions into local and far-field components, with a particular focus on charge rearrangements and the various contributions to the interaction energies (electrostatics, induction, dispersion, and charge transfer).
Beck and his research group use detailed computational modeling to understand the specfic behavior of ions in solution. Minor changes in the properties of an ion such as size or polarizability can have major effects on behavior. A thorough understanding of specific ion solvation phenomena has broad impacts in a range of fields including solution phase chemistry, biophysics, and sustainable energy storage. In addition, extensive examples from these important areas are included in both core undergraduate and graduate courses and special topics courses aimed at computational chemists. The PI is active in the development of a new curriculum for the Ralph Regula School of Computational Science in Ohio, and in mentoring under-represented undergraduates during their capstone research projects. A new overview course on Chemistry for Sustainable Energy is under development (aimed at a broad range of chemistry, physics, and engineering students), as well as a web-available set of active-learning modules for stimulating understanding of basic physical chemical principles.
