Metallic and Ionic Nanoparticles Extendable Structures: Reactivity, Catalysis, Adsorption.

Metallic and Ionic Nanoparticles

Extendable Structures: Reactivity, Catalysis, Adsorption

Extendable Structures: Reactivity, Catalysis, Adsorption© McREL 2009

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Nanoparticles


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Think

Coordination Numbers!

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Attracted to lots of nearest neighbors

High Coordination Numbers

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Low Coordination Numbers

Nanoparticles

Attracted to few nearest neighbors


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E (surface

atoms)

- E (interior

atoms)

Surface Energy!

= E (surface)

Nanoparticles

Higher energy!Surface atoms have


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Smaller Sample Larger Sample

Metallic CrystalNanoparticle

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…is where the interactions that result in changes in physical and chemical properties occur.

…is where chemical reactions take place.

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Factors that affect the RATE of chemical reactions

1. Size of reaction particles and increasing surface area 2. Concentrations of reactants3. Temperature

4. Presence of a catalyst

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As the size of nanoscale particles decreases,

the surface area to volume ratio increases.

Therefore, the surface energy increases!

What factors account for the increase in reaction rates of chemical processes at the nanoscale level?

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Adsorption takes place at the surface.

Nanoparticles


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7 grams of nanoparticles (four nm) have a surface area equivalent to a football

field

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Catalytic reactions takes place at the surface.

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Scanning Electron Microscop (SEM) showing the vertical growth of nanowires on a gold catalytic surface for electronic

devices (Stanford Nanofabrication Facility)

Gold Catalytic Surface

Nanowires

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Increase the rates of some chemical reactions

Decreases in the size of particles

Increases in surface area

Metallic and Ionic Nanoparticles


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Iron nanoparticles in YOUR backyard?

Nanoparticles

http://www.phschool.com/science/science_news/articles/special_treatment.html


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1. What chemical properties were most effected by surface energy?

2. How were the chemical properties affected by surface energy?

3. What physical properties might be affected by surface energy?

Making Connections


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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

Lesson 3.1Carbon Chemistry

Lesson 1.1 What is Nanoscience?

What is Nanoscience? Examine and Compare size: macro, micro, sub-micro (nano)SI prefixes

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 2.3Extendable Structures: Melting Point, Color Conductivity

Lesson 3.2Fullerenes and Nanotubes

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

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?

Module Flow Chart

Metallic and Ionic Nanoparticles Extendable Structures: Reactivity, Catalysis, Adsorption.

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