1 / 44

Where Chemistry Can Take You

Where Chemistry Can Take You. From the lab to the Stars From Utah to China, Japan & Switzerland by Terry A. Ring, Ph. D. Bingham High Chemistry. Earning a Living with Chemistry Talk about some of my research Making Powders by Crystallization[= Precipitation] Nucleation Crystal Growth

lyre
Download Presentation

Where Chemistry Can Take You

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Where Chemistry Can Take You From the lab to the Stars From Utah to China, Japan & Switzerland by Terry A. Ring, Ph. D.

  2. Bingham High Chemistry • Earning a Living with Chemistry • Talk about some of my research • Making Powders by Crystallization[= Precipitation] • Nucleation • Crystal Growth • Making Nano Particles • Nano Particles = Big Surprises • Demonstration • Clock Reaction • Ring’s Chemistry Competition

  3. Go to College and Get and Education • Why do your parents keep saying that?

  4. Education Pays

  5. What do you want to be when you grow up? • Many possibilities to use your scientific education! • Biologist • Chemist • Physicist • Engineer • Mathematician • Teacher • Doctor • Lawyer • YOUR DECISION HAS CONSEQUENCES! • $$$$$$

  6. How Much Do You Want to Earn When You Grow up?

  7. Job Growth • Chemistry Job Growth rate is ~14%/yr

  8. Do the Popular Professions Pay Well? • Which Job Pays More? • Computer Engineer? • Biologist? • Chemist? • Chemical Engineer?

  9. Salary Information Chem. Eng. • Median Salary for B.S. =$62,000/yr • Starting Salary ~$54,000/yr

  10. Starting Salary

  11. Crystalization Research

  12. CuNO3 + NaC2O4CuC2O4.xH2O Additives Control of Particle Shape Hydroxy propyl methyl cellulose additive HPMC adsorbs weakly on 100 +010 (equivalent) faces Acetate additive

  13. Epitaxial Aggregation Mixing - 1μs to 10 ms Nucleation - 10μs or mixing time Growth - 10μs or mixing time Aggregation - 10 ms Self Assembly - 10 ms CuOx

  14. Hexagonal Packing of Spheres • Light Diffraction

  15. Defects in Ordered Arrays Bend Light Optical Semiconductors

  16. Photonic Crystal Light Pipe Light Leaving Pipe Light Pipe

  17. Nano-sized Cluster Nucleation Terry A. Ring Chemical Engineering University of Utah • Introduction • Classical Nucleation Theory & Limitations • New Theory & Findings

  18. The Nanoscale is small! Conventional Machines (m - mm) Microelectronics (micron = 10-6 m) (10 cm down to 0.1 µm) Nanotechnology nanometer= 10-9 m (100 nm to 1 nm)

  19. Silicon Particles Introduction • Unique Properties of Nanosized Particles • Plasmon Resonance -color due to size, color change due to adsorption-sensors • Between Bulk and Atomic Electrical Properties • Catalytic Properties • Magic Cluster Sizes • C60, C70, C nanotubes, • Na clusters of 8, 20, 40, 58 and 92

  20. Stimulated Emission CdS Nano-Clusters-Laser • Lasing only when quantum dot concentration is sufficiently high. • Stimulated emission>Auger recombination • Klimov, V. Mikhailovsky, A.,Xu, S., Hollingswork, J., Malko, A., Bawendi, M., Eiser, H-J., Leatherhead, C.A. • Science 290,314 (2000) • Science 287,1011 (2000)

  21. Fullerene Synthesis Not Predicted By Theory!

  22. Nanoparticle Synthesis = Nucleation • Classical Nucleation Theory vs New Theory • Binding Energy per Li atom Kouteckky, J. and Fantucci, P., Chem. Rev., 86,539-87(1986). G(i) = - i kBT lnS + g ba ao2i2/3

  23. Population Balances • Classical Nucleation = Single Atom Addition • lij=(i+j), • Population Balance - Multi-atom Addition • lij=(i+j)exp(-DGij/kBT),

  24. Quantum Mech. Classical

  25. Population Comparison

  26. New Theory of Nucleation • Overcomes Limitations of Classical Nucleation Theory • Multi-atom addition • Free Energy driving force for Diffusion and Addition • Predicts Transients for Cluster Concentration of Each Size • Qualitative similar to Si Plasma Expts

  27. Collision Energetics

  28. Crystalloluminesent Spectrum • Intensity vs Energy • Intensity = collisions/per unit time = photons/unit time • Wavelength E = hc/l • Human eye detection @ 3x104photons/cm2/s at λ 510 nm Wavelength(nm) 2480 1240 827 620 496

  29. Similar to Line Spectra

  30. Crystalloluminescence • Term Schoenwald in 1786 • 30 References 1786 and 1957 • “An understanding of crystalloluminescence in not to satisfactory at the present time,” E.N. Harvey 1957 • Examples: NaCl, KCl, NaF, AsCl3, K2SO4, As3O3, Sr(NO3)2,, CoSO4, K2CO3, KHSO3, NaKSO4, NaKCrO4, NaKSeO4, Na2SO4, benzoic acid, and ice, water. • 16 References 1957-1991 (15 Russian+ 1 UK + 1 Italian Review) • “It is not possible to … provide either a unifying physical picture of the microscopic mechanism governing (crystalloluminescence) or a physical rule that allows (identification of) conditions...where the phenomenon is stronger,” Barsanti, M. & Maccarrone,,F., 1991 • 3 References from 1991-2000 (2 India, 1 Russian)

  31. Experimental Observations • Delay time is a function of concentration & mixing • Flashes are Short • < 80 ns • Peak Count rates • ~5-8x105 photons/s • Temporal & Spatial Bunching of Flashes • 340nm<λ<380 nm • Blue White Light Saturated NaCl + Conc. HCl - 120 s observation time Gibbon, M.A., Sopp, H. , Swanson, J., and Walton, A.J., J. Phys. C. 21,1921(1988).

  32. Spectra Has Series of Peaks • Different from • Thermal Luminescence • Photoluminescence • Impurities in Crystal have a Big Effect Spectrum Rabinerson, A.I. Wladimirskaya, M.A., Acta Physicochimica URSS, 10,859(1939)

  33. Makes New Predictions • Explains the reason for the occurrence of Magic Clusters and how the change with time. • Method to Quantitatively Measure Nucleation Events • Predicts Crystalloluminescent Spectrum • Where could we see Crystalloluminescence? • H2O Condensation Nucleation • Interstellar Dust Nucleation • Light from Deep Sea Vents

  34. Water Condensation due to Shock Wave

  35. Interstellar Dust Clouds - Light from the Fringe - Crystalloluminescence due to Nanocluster Nucleation

  36. Experimental Verification Nanocluster, Ti14C13 with emission peak at 20.1 microns is seen in Egg Nebula by A.G.G.M. Thielens and M.A. Duncan Science 288,313(2000) this joins some 120 other small molecules identified in the vicinity of stars, interstellar gas and dust clouds

  37. Super Novae

  38. Deep Sea Vents National Geographic October 2000 C&E News 12/21/98

  39. Deep Sea Life Salt Lake Tribune, 2/13/97 National Geographic October 2000

  40. Deep Sea Vents • Deep Sea Vents Spew Solublized Salts into the cold sea, causing Precipitation & Crystalloluminescence • In the Deep Ocean, Deep Sea Vents are the only source of Chemical Energy and Food • Mobile Animals need to be able to locate these Vents to eat - so they need eyes!! EAT AT JOE’S

  41. Once in a while you get shown the light….. In the strangest places… If you look at it right.

  42. Clock Reaction • The first step in this reaction is the formation of triiodide ion: • H2O2 + 3 I- + 2 H+ --> I3- + 2 HO • In the absence of thiosulfate ion the triiodide ion would form the characteristic blue complex with starch. However, the triiodide ion is rapidly reduced back to iodide ion by thiosulfate: • I3- + 2 S2O32- --> 3 I- + S4O62- • In this clock reaction thiosulfate ion is the limiting reactant. The blue starch-triiodide complex forms only when all the thiosulfate ion has been consumed.

  43. IO3- + 2 H2O2 + H+ = HOI + 2 O2 + 2 H2O (A) HOI + CH2(CO2H)2 = ICH(CO2H)2 + H2O (B)

More Related