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SUMMARY:Inside a Collapsing Bubble: Sonochemistry and Sonoluminescence - P
 rof Kenneth S Suslick\, Marvin T. Schmidt Professor of Chemistry\, Univers
 ity of Illinois
DTSTART:20161129T160000Z
DTEND:20161129T170000Z
UID:TALK68714@talks.cam.ac.uk
CONTACT:Alice Wood
DESCRIPTION:Inside a Collapsing Bubble: Sonochemistry and Sonoluminescence
 \nKenneth S. Suslick\nSchool of Chemical Sciences\nUniversity of Illinois 
 at Urbana-Champaign \n\nFundamentally\, chemistry is the interaction of en
 ergy and matter.  Surprisingly\, there are relatively few ways of putting 
 energy into molecules. High intensity ultrasound has found numerous applic
 ations in driving chemical reactions and in the preparation of unusual mat
 erials\, creating the field of sonochemistry.  The chemical effects of ult
 rasound originate from acoustic cavitation:  the formation\, growth\, and 
 implosive collapse of bubbles in a liquid.  From sonoluminescence spectros
 copy\, we have established that cavitation produces local conditions insid
 e the bubbles of ~5000 K\, ~1000 atm\, with heating and cooling rates that
  exceed 1010 K/s. In isolated single bubbles\, which can collapse more sym
 metrically and effectively\, temperatures exceeding 20\,000 K are observed
 .\nIn otherwise cold liquids\, ultrasound is able to drive reactions that 
 normally occur only under extreme conditions.  The sonochemical syntheses 
 of nanostructured metals\, alloys\, metal carbides\, supported heterogeneo
 us catalysts\, and nano-colloids derives from the sonochemical decompositi
 on of volatile organometallic precursors during cavitation\, which produce
 s clusters a few nm in diameter.  Such nanostructured solids are active he
 terogeneous catalysts for various reactions.  As examples\, we have discov
 ered a new synthesis of nanostructured MoS2 and Mo2C and of transition met
 al colloids of iron\, cobalt\, and iron-cobalt alloy colloids.  Sonication
  of molybdenum hexacarbonyl in the presence of sulfur produces a novel mor
 phology of MoS2 with extremely high activity for catalytic hydrodesulfuriz
 ation.\nAnother remarkable phenomenon occurs during ultrasonic irradiation
  of liquid-solid slurries: extremely high speed inter-particle collisions.
   Turbulent flow and shock waves produced by acoustic cavitation can drive
  metal particles together at sufficiently high velocities to induce meltin
 g upon collision. Metal particles that are irradiated in hydrocarbon liqui
 ds with ultrasound undergo collisions at roughly half the speed of sound a
 nd generate localized effective temperatures of ~3000 K at the point of im
 pact.  As a consequence\, both stoichiometric and catalytic liquid-solid r
 eactions can be tremendously enhanced. In addition\, sonofragmentation of 
 molecular crystals occurs readily\, which greatly improves the uniformity 
 of particles formed during crystallization\, for example\, of active pharm
 aceutical ingredients.\n\nFlannigan\, D. J.\; Suslick\, K. S. “Plasma Fo
 rmation and Temperature Measurement during Single-Bubble Cavitation” \nN
 ature 2005\, 434\, 52-55.\nSuslick\, K. S.\; Flannigan\, D. J. “Sonolumi
 nescence” Annu. Rev. Phys. Chem.  2008\, 59\, 659-683.\nBang\, J. H.\; S
 uslick\, K. S. “Applications of Ultrasound to the Synthesis of Nanostruc
 tured Materials” \nAdvanced Materials 2010\, 22\, 1039–1059.\nZeiger\,
  B. W.\; Suslick\, K. S. “Sonofragmentation of Molecular Crystals”  J.
  Am. Chem. Soc. 2011\, 133\, 14530-33.\nXu\, H.\; Zeiger\, B. W.\; Suslick
 \, K. S. “Sonochemical synthesis of nanomaterials”   Chem. Soc. Rev. 2
 013\, 42\, 2555-2567.\nYou\, S.\; Chen\, M.-W.\; Dlott\, D. D.\; Suslick\,
  K. S. “Ultrasonic hammer produces hot spots in solids” Nature Commun.
  2015\, 6\, 6581.\n\nKenneth S. Suslick is the Marvin T. Schmidt Research 
 Professor of Chemistry at the University of Illinois at Urbana-Champaign. 
 Professor Suslick received his B.S. from the California Institute of Techn
 ology in 1974 and his Ph.D. from Stanford University in 1978\, and came to
  the University of Illinois immediately thereafter. He is the recipient of
  the Centenary Prize and the Sir George Stokes Medal of the RSC\, the MRS 
 Medal\, the ACS Nobel Laureate Signature Award for Graduate Education\, th
 e ACS Senior Cope Scholar Award\, a Guggenheim Fellowship\, an NIH Researc
 h Career Development Award\, a Sloan Foundation Research Fellowship\, and 
 the Silver Medal of the Royal Society for Arts\, Manufactures\, and Commer
 ce\; he is a Fellow of the AAAS\, ACS\, RSC\, MRS\, APS\, and the Acoust. 
 Soc. Amer. He has published more than 360 papers\, edited four books\, and
  holds 42 patents and patent applications.\n
LOCATION:Pfizer LT
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