Metallic and Ionic Nanoparticles
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Metallic and Ionic Nanoparticles. Extendable Structures: Melting Point, Color, Conductivity. Iron Nanoparticles. How many grams of iron powder would it take to present a surface area equal to that of 1 gram of nanoparticles? ______.

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Metallic and Ionic Nanoparticles

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Metallic and Ionic Nanoparticles

Extendable Structures:

Melting Point, Color, Conductivity


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


Philosophical Chairs


Physical Properties

  • What physical properties are affected by the size of the nanoparticles?

High melting/boiling points

Conductivity

Color


Nanoparticles

Changes in Physical Properties

take place at

the surface!


Metallic Nanoparticles

What do these graphs tell us?


Gold Nanoparticles

How many atoms make it macro?


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.


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


Metallic Macroparticles

All colors of light

are reflected from a smooth silver

surface

Somebluelight is absorbedby 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


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


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


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?


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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