Nano Particles & Applications, S. Pratsinis
Sotiris Pratsinis, PhD, Professor and Head of the Department of Mechanical and Process Engineering at ETH Zürich, Switzerland, provides Nano World News with two exclusive stories: a preview of his upcoming Nanotech 2008 One-Day Workshop Functional Nanoparticles and Films made in the Gas-Phase, and an overview of the nanoparticle research that being conducted at his Particle Technology Laboratory at the ETH Zürich in Switzerland.
Nanotech Workshop Overview: Functional Nanoparticles and Films Made in the Gas-Phase
Dr. Pratsinis will lead a one-day workshop titled Functional Nanoparticles and Films made in the Gas-Phase at NSTI Nanotech 2008 in Boston Sunday, June 1. Dr. Pratsinis tells NWN, “The course will start with the fascinating history of this technology from ink production in ancient China and Greece to the Bible printing by Gutemberg in Mainz and to the current manufacture of optical fibers, carbon blacks, filamentary nickel, pigments and fumed silica through valiant Edisonian research.” Opportunities for aerosol synthesis of functional materials are highlighted in the course. An overview of aerosol reactors for synthesis of metal, alloys, ceramics as well as their composites is given. Fundamental physical and chemical phenomena that control these processes are presented along with engineering design principles combining fluid and particle dynamics. Emphasis is placed on scalable flame reactors that dominate both by value and volume today’s manufacture of nanostructured materials.
Nanoparticles made in flames: From right to left: yellow Bi
Dr. Pratsinis would like readers of the NWN to know that “this course will introduce aerosol process technology and show its accessibility and potential for manufacture of nanoparticles for catalysts, sensors, biomaterials, phosphors and even nutritional supplements. It will go through its history to show how it survived the “death valley of scale-up” from laboratory to manufacturing for selected products. The most important theories will be presented along with tangible examples so one can use them for a specific product with systematic reasoning and use of the pertinent literature. Diverse examples will be given through analyzing and discussing a number of old and new products and processes using dry technologies in a relaxed atmosphere and through motivating lectures.”
Particle Technology Laboratory, ETH Zürich, CH
(Overview courtesy of S. E. Pratsinis)
Particles are everywhere: from the air we inhale, to the bread, salt and pepper on the dinner table, in dental fillings, in every medication pill, in automobile tires and diesel exhaust, in the cement, wall or car paint, in every chocolate, cosmetics, suntan lotions etc.
The mission of our laboratory is to teach the fundamentals of particle science and engineering through basic research. We focus on the smallest particles, nanoparticles, as their properties are quite different than those of bulk materials creating unprecedented opportunities for the development of new products and processes as well as new challenges in handling and processing these particles. We specialize on gas-phase (aerosol) processes for their unique capacity to form high purity products (e.g. optical fibers) with closely controlled size, morphology, purity and composition accompanied by few, if any, liquid byproducts (1). As a generic aerosol process, we study closely flame technology for its potential to make a spectrum of particles for diverse applications and its proven scale-up capacity in manufacture of carbon blacks, fumed silica and titania (2).
A focus of our program is on understanding particle dynamics (3) during materials manufacture at high concentrations (4) and in particular the formation of aggregates and agglomerates (5) that greatly affect their processing and applications. Parallel to this and in close collaboration with top industrial and academic laboratories in ETH, Europe, U.S., Asia and Australia we focus on product discovery and quantitative process understanding for rational exploration and scalable synthesis (up to 1 kg/h at ETH Zurich) of novel materials for catalysts (6), ceramics (7), sensors (8), phosphors (9), dental fillings (10) and even nutritional supplenets (11) to name a few that may revolutionize technology in ways and that have never been considered before.
1. R. Strobel, S.E. Pratsinis, “Flame aerosol synthesis of smart nanostructured materials”, J. Mater. Chem., 17, 4743 - 4756 (2007).
2. K. Wegner, S.E. Pratsinis, Scale-up of nanoparticle synthesis in diffusion flame reactors, Chem. Eng. Sci., 58, 4581-4589 (2003).
3. G. Beaucage, H. Kammler, R. Mueller, R. Strobel, N. Agashe, S.E. Pratsinis, T. Narayanan, “Probing the dynamics of nanoparticle growth in a flame using synchrotron radiation“, Nature Mater., 3, 370-373 (2004).
4. M.C. Heine, S.E. Pratsinis, "High Concentration Agglomerate Dynamics at High Temperatures", Langmuir, 22, 10238-10245 (2006).
5. R. Grass, S. Tsantilis, S.E. Pratsinis, "Design of High-Temperature, Gas-Phase Synthesis of Hard or Soft TiO2 Agglomerates", AIChE J., 52, 1318-25 (2006).
6. R. Strobel, A. Baiker, S.E. Pratsinis, “Aerosol flame synthesis of catalysts: a Review”, Adv. Powder Technol., 17, 457-80 (2006).
7. R. Jossen, R. Mueller, S.E. Pratsinis, M. Watson and M.K. Akhtar, “Morphology and composition of spray-flame-made yttria-stabilized zirconia nanoparticles”, Nanotechnology, 16, S609-S617 (2005).
8. A. Tricoli, M. Graf, F. Mayer, S. Kühne, A. Hierlemann, S.E. Pratsinis “Micropatterning Layers by Flame Aerosol Deposition - Annealing”, Adv. Mater., in press, (2008).
9. A. Camenzind, R. Strobel, S.E. Pratsinis, “Cubic or Monoclinic Y2O3:Eu3+ nano-particles by one step flame spray pyrolysis", Chem. Phys. Lett., 415, 193-7 (2005).
10. H. Schulz, L. Madler, S.E. Pratsinis, P. Burtscher, N. Mozner, “Transparent nanocomposites of radiopaque, flame-made Ta2O5/SiO2 particles in an acrylic matrix”, Adv. Funct. Mater., 15, 830-837 (2005).
11. F. Rohner, F.O. Ernst, M. Arnold, M. Hilbe, R. Biebinger, F. Ehrensperger, S.E. Pratsinis, W. Langhans, R.F.Hurrell, M.B. Zimmermann “Synthesis, characterization, bioavailability in rats of ferric phosphate nanoparticles”, J. Nutr., 137, 614-9 (2007).
