Integrated Study of Nanopowder Synthesis and Pollutant Control using Electrically-Assisted Combustion

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The objective of this work is fundamental understanding of the mechanisms of particle formation, growth, and aggregation in combustion systems subjected to external electric fields and utilization of that understanding to define process conditions that enable both high-rate deposition of non-agglomerated nanopowders and control of pollutant particulate emissions. The ceramic nanopowders investigated Initially are silica (SiO2), titania (TiO2), alumina (Al2O3) and zirconia (ZrO2) using highly volatile precursors. The pollutant particulates investigated are soot and particulates containing toxic metals such as lead (Pb) and chromium (Cr). The consolidated research program deals with the effects of applying electric fields on formation of solid particles in flames and addresses concurrently issues in both materials synthesis and environmental engineering. Experiments are conducted in aerodynamically simple flow fields, i.e. flat-flame stagnation-point (premixed) and flat-flame counterflow (non-premixed), to characterize the effects of electric field and of other controllable process parameters (including pressure) on chemical composition, primary particle size, crystallinity, and degree of agglomeration. The use of multiple precursors to produce doped, coated, or mixed nanocyrstalline nanoparticlesis investigated. The characteristics of film deposition in an electric field are examined with respect to composition, morphology, deposition patterns, and sintering. Advanced laser diagnostics, electron microscopy, and X-ray diffraction are utilized to model and analyze the effects of flame structure (due to process inputs) on particle evolution. A computational model incorporating detailed gas-phase chemical kinetics and transport (including electric field effects) is developed along with models for particle formation, growth, and aggregation. Broader impact Among the processes that have been demonstrated for flame synthesis of nanopowders, the approach of applying electric fields is one of the most promising in terms of precise control of primary particle size, crystallinity, and aggregate size. The same methodology can be used for the control of particulate emissions from combustion systems used for power generation and incineration. The research and experimental facility are incorporated into the new curriculum onnanomaterials science and engineering being offered as a joint program between several departments and into the graduate curriculum on advanced experimental methods. The involvement of underrepresented minorities and women in engineering is increased by supporting undergraduate research as part of the Douglass Project for Rutgers Women in Math,Science, and Engineering. The training of students (at high school, undergraduate, and graduate levels) for the high-technology workforce is promoted by partnering with industry, state, and the Center for Nanomaterials Research..