SGER: Nanoparticle Shape Formation Mechanisms in Gas Phase Synthesis

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AbstractCTS-0423621Y. Xing, U of Missouri-RollaNanoparticles have become an important class of materials in nanotechnology research and development. The well-known, size-dependent properties of nanoparticles make it possible to control their electronic, optical, chemical, and mechanical properties. Indeed, over the past two decades there has been enormous research activity in the synthesis of size-controlled nanoparticles. While the size is an important factor in controlling nanoparticle properties, the recent success in the synthesis of shape-controlled nanoparticles has demonstrated yet another interesting aspect in nanoparticles, i.e., shape-controlled properties. The objective of this research is to explore the shape formation mechanisms of iron oxidenanoparticles synthesized in a gas-phase process. By conducting experiments using a specially designed counterflow diffusion flame reactor, together with theoretical approaches to nanoparticle deposition in thermal boundary layers, we aim to obtain a fundamental understanding of gas-phase nanoparticle shape formation and to learn if the shape formation is due to nanoparticle crystallization during the deposition process, and if so, how it is affected by the thermal boundary layers.Intellectual meritThe synthesis of shape-controlled nanoparticles had been achieved only in liquid phase before. Our recent results in the gas-phase synthesis of iron oxide nanoparticles demonstrated a more favorable way of producing shaped-controlled nanoparticles. This exploratory research will be the first attempt to gain a fundamental understanding of nanoparticle shape formation in gasphase processes. Such research is necessary to increase our ability to control and optimize the gas-phase synthesis technique for shape-controlled nanoparticles. Through the proposed study, new knowledge will be created in nanoparticle synthesis, as well as in nanoparticle dynamics and transport in thermal boundary layers. The proposed research, if successful, will establish the foundation for a future, multi-year project in the gas-phase synthesis of shape-controlled nanoparticles.Broader ImpactsNanotechnology is fast becoming one of the key enabling technologies for economic growth. A fundamental study as proposed in this project will enable the development of more efficient and less costly processes for nanomaterials production. Therefore, the proposed project would have significant societal and economic impacts. The project will involve integrated research and education for both graduate and undergraduate students. Undergraduate students will be actively involved in the project through their independent research class. Graduate students will obtain their training through thesis research in the proposed area. A high school student also will be involved through a summer program at the University of Missouri-Rolla. In order to broadly disseminate new knowledge and experience, results from this work will be presented at professional meetings, published in peer-examined journals, and made available on the World Wide Web.