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Metallic and Ionic Nanoparticles

Discover the impact of iron nanoparticles on TCE cleanup rates, cleansing ability, and surface properties. Learn about physical changes at the nano level and how energy and motion of valence electrons shift. Uncover the differences between nanosamples and macrosamples of the same substance.

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Metallic and Ionic Nanoparticles

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  1. Metallic and Ionic Nanoparticles Extendable Structures: Melting Point, Color, Conductivity

  2. Iron Nanoparticles • How many grams of iron powder would it take to present a surface area equal to that of 1 gram of nanoparticles? ______ • How would iron nanoparticles affect the rate of TCE cleanup? • _____ liters of water can be cleaned by one gram of iron nanoparticles. • Why is the cleansing ability estimate such a wide range?

  3. Iron Nanoparticles in Your Backyard http://www.phschool.com/science/science_news/articles/special_treatment.html

  4. Iron Nanoparticles in Your Backyard

  5. Philosophical Chairs

  6. Physical Properties • What physical properties are affected by the size of the nanoparticles? High melting/boiling points Conductivity Color

  7. Nanoparticles Changes in Physical Properties take place at the surface!

  8. Metallic Nanoparticles What do these graphs tell us?

  9. Gold Nanoparticles How many atoms make it macro?

  10. Gold Nanoparticles 5 nm diameter gold nanoparticles The image represents nanoparticles in suspension. All of them are the same size. Those that appear smaller are further away.

  11. Ionic Nanoparticles Adapted from F. G. Shi, J. Mater. Res., 1994, 9(5), 1307-1313,reproduced in Nanoscale Materials in Chemistry, edited by Kenneth J. Klabunde, 2001, John Wiley & Sons, Inc, New York, NY

  12. Metallic and Ionic Nanoparticles Decreased melting points Increased rates of some chemical reactions Increased surface area to volume ratios of nanoparticles

  13. Gold Particles Bulk Gold Nano Gold 2-3 mm diameter gold beads in toluene 4-5 nm diameter gold nanoparticles in toluene Courtesy of Kansas State University

  14. Metallic Macroparticles All colors of light are reflected from a smooth silver surface Somebluelight is absorbedby a smooth gold surface

  15. Metallic Nanoparticles • As the size of the nanoparticles decrease and • shapes change to include more edge and corner sites, • the ENERGY and MOTION of valence electrons change.

  16. Metallic Nanoparticles At the nano level • light interacts with surface electrons • electrons move in unison, forming waves • electron waves behave as if they were a single, charged particle, interacting with only specific wavelengths of light

  17. Gold Silver Color of lustrous macro samples Metallic Nanoparticles As particle size decreases, electromagnetic radiation interacts with free electrons to absorb, reflect, or transmit different colors of light. Larger Smaller Color transmitted through stained glass windows

  18. Electrons in Metals Electrons in Atomic Orbitals “sea of electrons” s, p, d, and f atomic orbitals random motion electrons can be elevated to higher energy levels

  19. Metallic Nanoparticles As particle size decreases, conductivity decreases

  20. Extendable Nanoparticles How and why do the chemical and physical properties of nanosamples differ from those of macrosamples of the same substance?

  21. Making Connections • Name three physical properties that are affected by surface energy? • How were the physical properties affected by surface energy? • What do you think is the difference between extendable and discrete nanoparticles?

  22. Module Flow Chart Lesson 1.1 What is Nanoscience? What is Nanoscience? Examine and Compare size: macro, micro, sub-micro (nano) SI prefixes Lesson 1.2 What Makes Nanoscience so Different? What makes Nanoscience so different? Compare Newtonian and Quantum Chemistry Regimes as they relate to nanoscale science Lesson 1.3 What Makes Nanoscience so Important? Interdisciplinary science The development of new technologies and instrumentation applications whose risk and benefits have yet to be determined Poster Assessment Students will further investigate the essential question that they have considered throughout the module: How and why do the chemical and physical properties of nanosamples differ from those of macrosamples? Lesson 2.1Extendable Solids As the size of the sample decreases the ratio of surface particles to interior particles increases in ionic and metallic solids Lesson 2.2Extendable Solids: Reactivity, Catalysis, Adsorption The difference between the energy at the surface atoms and energy of the interior atoms results in increased surface energy at the nanoscale Higher surface energy allowing for increased reactivity, adsorption and catalysis at the nanoscale Lesson 2.3 Extendable Structures: Melting Point, Color Conductivity In Extendable Structures: Melting point decreases because surface energy increases Color changes because electron orbital changes with decreased particle size Electrical conductivity decreases because electron orbital changes with decreased particle size Lesson 3.1 Carbon Chemistry Lesson 3.2 Fullerenes and Nanotubes

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