The combined use of ab initio computational chemistry and experimental spectroscopies in addressing engineering problems is becoming an increasingly widespread approach. This CAREER project will emphasize the combination of theory and experiment both in performing fundamental research and in educating students with diverse levels of experience. The research component focuses on development of a new model system that will enable detailed investigations of the chemistry and physics of metal-insulator interfaces. These interfaces are important for an array of applications, including microelectronics engineering, heterogeneous catalysis, and chemical sensing, but have been difficult to study using experiment or theory because they are typically "buried" under a continuous solid layer. In this project, model interfaces that are accessible to both experimental and theoretical techniques will be formed by adsorption of SiO2-like spherosiloxane clusters onto catalytic metal single crystal surfaces. A battery of experimental techniques will be used to characterize the adsorption and reaction of spherosiloxanes, varying the composition and morphology of the metal substrate along with the size of the spherosiloxane clusters. Results from first-principles computations will be used in interpreting experimental observations, helping to understand the molecular-level structure of the interfaces formed. Once characterized, the model interface will be used to study the mechanism for an important application: the detection of H2 gas using metal-oxide-semiconductor devices. Teams of graduate and undergraduate students who participate in this research will gain broad experience in theoretical principles, advanced spectroscopic techniques, and real-world applications. This synergy of theory, spectroscopic techniques, and application development will be emphasized in instructional activities as well. In these efforts, we will exploit the utility of computational chemistry software for aiding students in visualization of chemical reactions at the molecular scale. A new graduate/advanced undergraduate course will focus on analysis of chemical reaction processes in terms of molecular-scale transformations, with students' use of computational chemistry software representing a key component of the course. Molecular modeling simulations will also be introduced on a more basic level in undergraduate courses, where they will provide both a method for analysis of thermodynamics and reaction kinetics and an effective demonstration tool for visualization of reaction processes. These demonstrations will also be used in outreach to area high schools, emphasizing elementary chemistry concepts while at the same time exposing young students to an important, growing area of research that makes use of computer technology. Finally, this career plan calls for development of a web module that provides simple explanations and examples for computational chemistry concepts; this web site will be accessible to graduate, undergraduate, and high school students. The web module will be an essential tool in achieving all the educational goals of this project, including those relevant for graduate, undergraduate, and high school students. Thus, the overall impact of these activities will be the development of both a combined experimental/theoretical approach to a specific engineering problem-the chemistry of metal-SiO2 interfaces-and educational tools that will encourage students to use this synergistic approach in dealing with engineering problems in general.
