Alberto Striolo
School of Chemical, Biological and Materials Engineering
The University of Oklahoma
History teaches that answering fundamental questions yields revolutionary scientific advances with an array of practical applications. For example, the success of the Manhattan Project was due, in part, to the ability to separate isotopes.
Our group is interested, among other projects, in understanding the properties of aqueous electrolyte solutions at interfaces. The fundamental questions we seek to answer include: (A) how does a solid structure perturb interfacial water? (B) How far from the solid does this perturbation persist? (C) What is the rate of water reorientation and exchange in the perturbed layer? (D) What happens in the presence of simple electrolytes? To address such issues we employ an arsenal of theoretical methods spanning from electronic structure calculations, through atomistic molecular dynamics, to coarse-grained Monte Carlo simulations. Because we strongly believe that theoretical and experimental investigations should proceed synergistically coupled, we routinely test our theoretical predictions by conducting appropriate experiments.
In this talk we will present recent molecular dynamics simulation results for water and simple electrolytes near silicon dioxide surfaces of various degrees of hydroxylation. The data suggest the formation of a layered aqueous structure near the interface, as qualitatively confirmed by experiments conducted on a custom-made atomic force microscope. Further, the density profile of interfacial water seems to dictate the density profiles of aqueous solutions containing NaCl, CaCl2, CsCl, and SrCl2 near the solid surfaces. These results suggest that ion-ion and ion-water correlations should be considered when it is desired to predict the distribution of electrolytes near a charged surface. We will discuss experimental techniques that could be used to validate our predictions, as well as several practical applications that will benefit from the successful completion of our project. These applications include, but are not limited to water desalination, exploitation of the oil shale in the Green River Basin, nuclear waste sites remediation, and design of nanofluidic devices.
Dr. Striolo’s lab combines experimental and computational approaches to study various chemical phenomena, including aqueous electrolyte solutions, surfactant self-assembly and adsorption as well as heterogeneous catalysis.
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