Alenka Luzar of Virginia Commonwealth University is supported by the Chemical Theory, Models and Computational Methods program in the Division of Chemistry to study the properties of aqueous (water) interfaces at the nanoscale. The work focuses on interfaces when electric fields are present. Aqueous interfaces pervaded by electric fields are ubiquitous in nature, for example in human cells. They are also important in many engineering applications. Modulation of static and dynamic properties of such interfaces underlies the function of biological membranes, heterogeneous catalysis, and development of lab-on-a chip technologies. Luzar and co-workers address some of the fundamental aspects of these phenomena. The molecular picture this research provides enables the design of new electromechanical devices of nano- or microscale dimensions. New methodologies are being developed to enable more realistic predictions of materials' properties, for example the propensity of metals to bind polar molecules, including biological ones. The research is very inter-disciplinary and very fundamental. It is highly appropriate for training and motivating students, including undergraduates, to become scientists.
Professor Luzar and her co-workers develop and apply novel computational approaches to elucidate water responses to heterogeneous environments, both in and out of equilibrium. Three separate, but interconnected areas are being investigated: (1) Characterization of high frequency polarization response of interfacial water, its relation to hydrogen bond dynamics, and the interplay of confinement and external field effects on molecular reorientation; (2) Timely problem of mechanical to electric energy conversion based on the reversal of electroactuation, where an immense improvement upon transition to nano- or mesoscale is envisaged. New nonequilibrium molecular dynamics methodology to capture heat exchange associated with friction and ohmic dissipation under electromechanical perturbation are being introduced within the framework of constant voltage Molecular Dynamics. New algorithms for surface tension, line tension and friction impeding liquid spreading under applied field are being developed; (3) Hydration of, and solvation forces between nanoscale solutes with multi-body interactions associated with materials conductivity, beyond the polarization of individual moieties. A computational approach to large-scale polarization effects characterizing conducting particles subject to the fixed potential requirement is being developed for systems comprising metallic or semiconducting particles.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
