CAREER: Kinetics and Engineering of Functional Nanoscale Organic-Inorganic Hybrids

University Of Kentucky Research Foundation, Lexington KY

Investigators

Abstract

This CAREER grant combines research and educational initiatives in the area of bringing the control of organic-inorganic hybrid materials synthesis closer to the level of control currently enjoyed for organic polymers. Research: The synthesis of organic-inorganic hybrid materials will be investigated with a combination of in-situ kinetic experiments and computer modeling. These materials consist of organic and inorganic components combined during the polymerization of alkoxysilane precursors. In the short term, the PI will focus on amine-functional silanes and their mixtures with regular silica-forming precursors. Later he will also investigate alkylene bridges and other common functional groups such as mercaptopropylsilanes. He plans to develop and apply kinetic models of the reactions of these precursors, capturing the competition of reactions among and between components. He hypothesizes that cyclization to form small (6- to 10- atom) rings plays a significant role in the structure development of these precursors. He will compare the implications of these rings for precursors with dangling organics and with organics bridging pairs of silane units. By determining the kinetic parameters for reaction among and between the precursors, he will quantitatively relate synthesis parameters (monomer, water and catalyst concentrations, solvent type, addition rate, etc.) and the molecular homogeneity and structure of the growing hybrid. The models will require both continuum and dynamic Monte Carlo simulations, and can be used to optimize homogeneity. Broad Impact: Greater understanding of the polymerization kinetics of organically modified aloxysilanes will impact the synthesis of materials for diverse applications including chromatography, catalysis, adsorption, biomedical and dental materials, environmental remediation, and coatings. Educational activities will include the development of a course on inorganic materials chemistry and engineering. This will be an upper-level elective designed so that it is directly related to, and provides modular instructional materials for, core chemical engineering classes. The PI will also implement computational tools throughout the chemical engineering curriculum, starting with a course for students in their first two years of college, including an upper-level molecular simulation elective.