Measurement of Sub-2 nm Clusters of Pristine and Composite Metal Oxides during Nanomaterial Synthesis in Flame Aerosol Reactors


Measuring stable clusters to understand particle inception will aid the synthesis of well-controlled nanoparticles via gas-phase aerosol routes. Using a Half Mini differential mobility analyzer, the presence of monomers, dimers, trimers, and tetramers was detected for the first time in a flame aerosol reactor during the synthesis of pristine TiO2 and TiO2/SiO2 nanocomposites. Atomic force microscopy confirmed the presence and the size of sub-2 nm clusters. The detection of these clusters elucidated the initial stages of particle formation during combustion synthesis and supported previous hypotheses that collisional growth from stable monomers of metal oxides is the first step of particle growth.


Civil, Architectural and Environmental Engineering


This work is based upon work supported in part under the U.S.-India Partnership to Advance Clean Energy-Research (PACE-R) for the Solar Energy Research Institute for India and the United States (SERIIUS), funded jointly by the U.S. Department of Energy (Office of Science, Office of Basic Energy Sciences, and Energy Efficiency and Renewable Energy, Solar Energy Technology Program, under Subcontract DEAC36-08GO28308 to the National Renewable Energy Laboratory, Golden, Colorado) and the Government of India, through the Department of Science and Technology under Subcontract IUSSTF/JCERDC-SERIIUS/2012 dated 22nd Nov. 2012. The authors gratefully acknowledge the help and support of Professor Juan Fernandez de la Mora, Yale University, and Professor Chris Hogan, University of Minnesota, for their help on the use of the Half Mini DMA.

Keywords and Phrases

Aerosols; Atomic force microscopy; Combustion synthesis; Monomers; Titanium dioxide; Composite metal oxides; Differential mobility analyzers; Flame aerosol reactor; Nanomaterial; Particle formations; Particle growth; Particle inception; Stable clusters; Dimers

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Article - Journal

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© 2014 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Aug 2014