Joint Seminar
Environmental Engineering Science and Chemical Engineering

Monday, February 7, 2005
Time: 2:30 pm
Cupples II, Room 100

"Synthesis of Functional Nanoparticles in Flame Aerosol Reactors"

Dr. Sotiris E. Pratsinis
Institute of Process Engineering,
Department of Mechanical and Process Engineering, Swiss Federal Institute of Technology (ETH Zurich),
CH-8092 Zurich, Switzerland
http://www.ptl.ethz.ch/
 

    The lecture will start with a fascinating historic overview of aerosol technology from ancient China and Greece to the current manufacture of SiO2, TiO2, Ni and carbon black commodities. Recent advances in the scientific understanding of aerosol formation and growth allow now optimal aerosol reactor design and inexpensive production of sophisticated nanoparticles with controlled composition, size and morphology leading to exciting new products.  
    Silica particles thinly- or spot-coated with titania (1-2%) in flames lead to production of highly selective epoxidation catalysts at production rates of 500 g/h. Flame-made titania particles coated in-situ with vanadia monolayers lead to selective catalytic reduction of NOx with NH3 at lower temperatures than conventionally made catalysts giving the potential for better fuel utilization and more effective pollutant (e.g. Hg) removal during incineration.
Noble-metal clusters on ceramic nanoparticles are made by flame spray pyrolysis resulting in efficient catalysts for manufacture of chiral ethyl pyruvate for pharmaceuticals. Stable quantum-dots of ZnO for UV filters can be made by in flames by co-precipitation with SiO2 without fractionation.
    Emphasis is placed now on the fundamentals of flame spray pyrolysis for synthesis of ZrO2 particles and on the distinction between hard- and soft-agglomerates if time permits.


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