Abstract

Gas-phase synthesis of nanoparticles is attractive as it offers fewer process steps, easier collection from process streams and fewer liquid byproducts than wet-chemistry routes. As a result, it is the preferred route for large scale manufacturing of fumed SiO₂, pigmentary TiO₂, filamentary Ni and carbon black. The lecture will start with an overview of flame aerosol technology from ancient China and Greece to the current manufacture of commodities. Recent advances in 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 new heterogeneous catalysts and directly-deposited gas sensors that are highlighted here, as well as to biomaterials, phosphors and even nutritional products (J. Mater. Chem. 17, 4743:2007).
Emphasis is placed now on large scale manufacture of these particles. At these conditions agglomerate particles are formed with collision areas far larger than their equivalent sphere resulting in high concentrations (up 10 vol%) where coagulation no longer follows the classic theoretical framework of Fickian flux to the particle surface. A new coagulation rate is developed from first principles for high concentration particle dynamics.
 

 

Speaker Biography

Professor Sotiris E. Pratsinis (Ph.D., UCLA 1985) was born on March 21, 1955 in Chanea, Krete, Greece. Since 1998, he has been Director of the Particle Technology Laboratory and since 2007 Head of the Department of Mechanical and Process Engineering at the Swiss Federal Institute of Technology (ETH Zurich). He has graduated 20 Ph.D. students and currently advises eight. His research program focuses on the fundamentals of aerosol synthesis of functional particles for catalysts, sensors, dental nanocomposites, nutrition, electroceramics etc. He and his students have published over 200 refereed journal articles, received seven European and U.S. patents licensed to various industries and contributed to creation of four spinoffs. He received the 1988 Kenneth T. Whitby Award of the American Association of Aerosol Research, the 1989 Presidential Young Investigator Award from the U.S. National Science Foundation, the 1995 Marian Smoluchowski Award of the European Association for Aerosol Research and the 2003 Thomas Baron Award of the American Institute of Chemical Engineers. In 2005-06 he was appointed Russell Severance Springer Visiting Professor at the Mechanical Engineering Department of the University of California, Berkeley. He is on the Editorial Boards of the Journal of Nanoparticle Research, Particle and Particle Systems Characterization, KONA Powder and Particle, Powder Technology, Journal of Aerosol Science and Advanced Powder Technology. He also is on the Advisory Board of the Australian Research Council Centre on Functional Nanomaterials and on the Science Advisory Board of the Harvard School of Public Health - International Initiative for the Environment and Public Health.