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

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?

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

Iron Nanoparticles in Your Backyard Date of Test 12/01/02 1/06/03 2/03/03 Distance from Injection Well 1 TCE Concentration ppb pH TCE Concentration 8 ft (2.4 m) 41,000 6.92 100 7.87 160 8.51 10 ft (3.6 m) 5,100 6.77 47 8.18 79 8.61 20 ft (7.1 m) 7,400 6.91 690 7.08 610 7.17 Distance from Injection Well 2 0 ft (0 m) 88,000 7.32 11 8.24 78 8.27 6 ft (1.8 m) 76,000 6.9 420 8.52 730 7.91

Philosophical Chairs

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

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

Metallic Nanoparticles What do these graphs tell us?

How many atoms make it macro? Gold Nanoparticles How many atoms make it macro?

5 nm diameter gold nanoparticles New already created image needs to be inserted. 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. Metallic and Ionic Nanoparticles Extendable Structures

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

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

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

are reflected from a smooth silver Metallic Macroparticles All colors of light are reflected from a smooth silver surface Some blue light is absorbed by a smooth gold surface

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.

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

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

electrons can be elevated to higher energy levels 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

As particle size decreases, conductivity decreases Metallic Nanoparticles As particle size decreases, conductivity decreases

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

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? Judy add new screenshot Metallic and Ionic Nanoparticles Extendable Structures

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 2.1 Extendable Solids As the size of the sample decreases the ratio of surface particles to interior particles increases in ionic and metallic solids Lesson 2.2 Extendable 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