Flame aerosol synthesis of nanostructured materials and functional devices: Processing, modeling, and diagnostics

Manufacturing of nanostructured materials and functional devices offers many exciting opportunities for substantial contribution in renewable energy utilization, environmental compliance, and product development. In the past two decades, gas-phase flame synthesis has not only proved to be one of the most scalable and economical technologies for producing well-controlled nanostructured materials, including single metal-oxide, mixed-oxide nanocomposite, and carbon nanostructures, but also has been recognized as robust fabrication method of nano-devices. In this paper, we focus our review mainly on the recent trends in specific applications of flame aerosol synthesis in the last decade, e.g., (a) usage of a substrate in stagnation geometry with controlled particle temperature–time history, (b) application of external fields to control particle characteristics, (c) development of advanced spray technique for doping synthesis of nanocomposites of multicomponent metal oxides or carbon–metal oxides, and (d) fabrication of nanomaterial-based functional devices. For the possibility to improve the design and operation of flame aerosol reactors, we summarize recent advances in: (i) in situ optical diagnostics for either gas phase or particle phase in flame field; (ii) multi-scale modeling and simulation employing gas-phase chemistry, population balance method, molecular dynamics and nanoscale particle dynamics.