Heath Turner

The formation and structural/chemical evolution of nanostructured materials involves processes that span a wide range of time and length scales.  This includes bond-breaking and bond-formation steps, as well as concerted structural relaxations within the materials.  These events have characteristic time scales ranging from femtoseconds up to minutes/hours, so preserving atomistic details in a single computational model is particularly problematic.  In this presentation, I will describe kinetic Monte Carlo (KMC) approaches that we have developed for capturing the relevant kinetics and equilibrium thermodynamics in amorphous materials, along with applications to several different materials platforms.  Due to the underlying event-based nature of the KMC simulation technique, time scales can be extended by several orders-of-magnitude, well beyond traditional atomistic simulation approaches.  Furthermore, we have developed an automated process for cycling between KMC and MD stages; the KMC events are able to capture the reaction events (potentially involving long time scales), while the MD simulations are able to capture events involving concerted motions during structural relaxation.  The relative computational efficiency of our hybrid KMC-MD method allows for large parameter spaces to be rapidly explored, as well as automated feedback comparisons against experimental benchmark data.  Several different applications will be highlighted: (a) growth of Au nanoparticles in solution; (b) gas separation performance of ionic polyimide membranes; (c) growth of amorphous tribofilms on metal surfaces; and (d) dehydrochlorination of PVC plastic.

Prof. Turner completed his B.S. in Chemical Engineering from Auburn University and his Ph.D. in Chemical Engineering from NC State University.  He spent several years in industry with Monsanto, Birmingham Steel, and Trinity Consultants.  He joined the University of Alabama as an Assistant Professor in 2003, and he is now a Professor and Head of the Department of Chemical and Biological Engineering, and he is the inaugural Director of the UA Polymers and Soft Materials (Poly-SM) Research Center.  Over the past several years, he has been a visiting Faculty Fellow at NASA-Langley, the Naval Research Lab, and the Air Force Research Lab, Visiting Professor at Vanderbilt University, and an International Distinguished Professor at Shanghai University of Engineering Science.  He has published approximately 125 journal articles in the areas of computational catalysis, interfacial phenomena, ionic liquids, and polymers, with the goal of making stronger connections to experimental observables.

• Time: 11:00 AM
• Location: 206 Furnas Hall