CAREER: Advancing Mechanistic Understanding of Nanocrystal Dissolution in Aqueous Environments

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Nanomaterial dissolution in water is integral to a variety of chemical processes including corrosion, degradation, decomposition and catalysis. However, several factors including temperature, solution pH and chemistry, electrostatic potential, crystallite size and morphology, structural defects and the challenge of detecting short-lived reaction intermediates limit our understanding of dissolution mechanisms. In this proposal, the principal investigator aims to establish mechanistic pathways and rates of dissolution across several materials classes with the primary goal of providing a unified picture of the dissolution process using computational techniques. This new understanding will help identify experimentally hypothesized mechanisms, suggest ambient conditions to drive dissolution reactions along preferable routes, and aid the design of materials less prone to dissolution. The research results will be integrated into the engineering curriculum and a summer workshop will be organized to train high-school teachers on topics related to computational materials science.This proposal aims to develop a theoretical foundation of materials dissolution at the nanoscale by employing fully quantum-mechanical simulations to provide a complete picture of dissolution phenomenon through a tight integration of thermodynamic and kinetic studies. Experimental studies of nanoparticle dissolution are rather challenging as this transient process depends strongly on multiple interrelated factors. The PIs propose to use atomistic simulations capable of sampling statistically rare events which will enable insights into dissolution at a single event level under well controlled conditions. The outcome of the proposed activities will be fundamental understanding molecular mechanisms controlling interfacial behavior of nanomaterials by utilizing first-principles theoretical/computational approaches. Understanding the fundamental link between stability and activity of materials is expected to lead to efficient and rational design of new materials via selective dissolution/etching for improving catalyst performance. The goal of the education part of this proposal is to implement cooperative group learning strategy as an efficient problem-solving instructional approach into the engineering curriculum at UNL and evaluate its impact on student learning and teamwork skills. A summer school on integrated materials education will be hosted by the principal investigator at the University of Nebraska-Lincoln, in collaboration with the Nebraska Department of Education, to train high-school teachers on theory, simulation and scientific computing tools with the goal of developing instructional material that can be integrated into the curriculum of Nebraska high schools to attract students into STEM careers.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.