Atmospheric Fullerene Chemistry: Elucidating Oxidative Pathways and Characterization of Corresponding Derivatives

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NSF 13-1179Environmental Health and Safety of NanotechnologyProgram Manager: Dr. Barbara KarnProposal #1236865Atmospheric Fullerene Chemistry: Elucidating Oxidative Pathways and Characterization of Corresponding DerivativesAbstract: Carbon based nano-scale materials such as fullerenes and nanotubes in particular have been proposed for a variety of applications and are now on track to be widely produced at the industrial scale. Of particular interest, and currently deeply lacking in information/data, is the role of atmospheric processes (e.g. oxidizing reaction scenarios) to significantly alter a wide breadth of fullerene environmental behavior(s) including: solubility, (bio)availability, reactivity, stability, toxicity and overall environmental impact. This project is designed to fundamentally evaluate the reactivity (including kinetic and derivative analyses) of solid state and aqueous available fullerene species under various, highly controlled, atmospheric conditions, focused on oxidation pathways. The overarching hypothesis of this project is that C60, as a model fullerene, can be chemically oxidized and physically altered by a variety of oxidative, yet ubiquitous, processes in the atmosphere. Sub-hypotheses include: (A) Multiple, competing oxidative reactions occur simultaneously, albeit with different kinetics, resulting in corresponding and various derivatives; (B) Under "wet" conditions (10% RH), fullerenes will become increasingly hydrophilic, dissolving aggregates, with hydrolysis as major reaction after initial oxidation; (C) Model (atmospheric) organics and inorganics in the gas phase will modify these kinetics; (D) Reaction products from "wet" reactions (10% RH) will be relatively stable in aqueous systems; whereasunder "dry" reaction conditions, derivatives will continue to react with water upon aqueous exposure.Intellectual Merit: At the conclusion of this project, we will have a vastly improved understanding of environmentally relevant chemical mechanisms/pathways and physico-chemical factors that control the rate and extent of fullerene aggregation, transformation(s) and stabilities under atmospheric conditions. This information will provide fundamental understanding for material life cycle(s) in addition to aiding in the interpretation of fullerene toxicological studies. Results will also provide information regarding fullerene stability, storage and commercial applications, and will contribute to the development of green fullerene chemistries.Broader Impacts: In addition to creating and disseminating new technical knowledge needed for decision-making regarding an industrially produced, engineered nanomaterial; this project (platform) is designed to broadly impact both undergraduate and graduate education and research, in addition to contributing to specific K-12 outreach programs. Graduate and undergraduate(project integrated) education and highly interdisciplinary research will strengthen our human resource base in an emerging need area where qualified researchers are in short supply, yet needed for the development of sustainable nanotechnologies. Furthermore, PI's will support and work directly with educators and students, providing expertise and regular mentoring at the St. Louis' Knowledge is Power Program (KIPP): Inspire Academy, preparing students for local, regional and international science fair projects and competitions.