Paper AS-TuA4
First Principles Thermodynamics and Molecular Modeling of Surfaces in Aqueous Environments

Tuesday, October 23, 2018, 3:20 pm, Room 204

We have been using first-principles thermodynamics and molecular modeling to characterize the structure, stability and dynamics of solid surfaces in aqueous environments. This talk will focus on two recent examples from our research. The first involves understanding and predicting the thermodynamics of the corrosion of stainless steel and nickel alloys in contact with the coolant in nuclear pressurized water reactors, as well as the driving force that leads to unwanted deposits on the fuel rod cladding from the corrosion products. The second example is a molecular modeling study of the adhesion of functionalized nano-diamond clusters to a gold substrate. Our simulations have revealed a new phenomenon, a molecular water layer containing solvated counter ions between a gold substrate and a negative nano-diamond that is facilitated by surface functionalization, and that is not present for a positively charged nano-diamond. The resulting electro-static screening leads to a weaker adhesion of negative nano-diamonds compared to positive nano-diamonds, an effect that has been observed in prior experiments but not understood.

This work was supported by the Consortium for Advanced Simulation of Light-Water Reactors, a DoE Energy Hub, and by the National Science Foundation through grant DMR-1535082.