Engineering Physics
Chapter 8
Nanophysics
Kazim Marfatiya
Mihir Prajapati
Harsh Mehta
Presented By:
Government Engineering...
Contents
 Nanomaterials and Nanotechnology
• Aspects of Nanotechnology
• Approaches in Nanotechnology
• Nanotechnology: S...
Nanotechnology
• the branch of technology that deals with dimensions and tolerances of
less than 100 nanometers, especiall...
Aspects of nanotechnology
Direct
Application of novel,
Nano engineered
artifacts
Ex : Electronic &
photonic circuits
Indir...
Creating Nano-scale materials by
physically or chemically breaking down
larger materials
Assembling Nano materials atom-
b...
Nanotechnology: Size and Scale
Application Of Nanotechnology
Agrochemical
Ex: Nanoparticles in
pesticides
Convergence
Nano-Geo-(Bio)-Info
technology
In f...
Nano powders - building blocks of Nano materials
(particles less than 100 nm in size)
Nanoparticles of gold for
new cataly...
Properties Of Nano
materials
Optical Property
• Due to surface Plasmon resonance
• Due to the increased energy level spacing
Mechanical Property
• Disl...
Hardness and strength
• Increase with (grain diameter)-1/2 (Hall- Patch equation)
• since grain boundaries: barrier agains...
Some Other Properties of Nanomaterial
High Strength, Hardness, Formability and toughness
More Brittle
Super Plasticity
Mag...
Disadvantages of Nanomaterials
Impurities
Since nanomaterial are
highly reactive ,they
inherently interact with
impurities as well. In
addition, encapsul...
It is extremely hard to
retain the size of
nanoparticles once they
are synthesized in a
solution.
Hence, the nanomaterial
...
Instability of particles
Retaining the active metal
nanoparticles is highly
challenging , as the kinetics
associated with
...
Effect On Human Body
Nanoparticles are small enough to
be absorbed by the skin and cause
irritation and have indicated to ...
Some more disadvantages of nanomaterials..
Chemicals in the form
of tiny nanoparticles
have been shown to
spread throughou...
Nanotech and Material's Property, Application and Disadvantages
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Nanotech and Material's Property, Application and Disadvantages

This presentation is on Chapter 8 : Nanophysics Of G. Vijyakumari book for GTU.It is made by me...
Published on: Mar 3, 2016
Published in: Engineering      Technology      Business      
Source: www.slideshare.net


Transcripts - Nanotech and Material's Property, Application and Disadvantages

  • 1. Engineering Physics Chapter 8 Nanophysics Kazim Marfatiya Mihir Prajapati Harsh Mehta Presented By: Government Engineering College, Modasa
  • 2. Contents  Nanomaterials and Nanotechnology • Aspects of Nanotechnology • Approaches in Nanotechnology • Nanotechnology: Size and Scale  Unusual Properties of Nanomaterials  Disadvantages of Nanomaterials
  • 3. Nanotechnology • the branch of technology that deals with dimensions and tolerances of less than 100 nanometers, especially the manipulation of individual atoms and molecules • Nanotechnology is engineering at the molecular (groups of atoms) level • It is the collective term for a range of technologies, techniques and processes that involve the manipulation of matter at the smallest scale (from 1 to 100 nm2)
  • 4. Aspects of nanotechnology Direct Application of novel, Nano engineered artifacts Ex : Electronic & photonic circuits Indirect Progressive miniaturization of existing technologies Ex : Nano bots, cosmetics Conceptual All materials & processes are considered from a molecular viewpoint Ex : Universal manufacturing model
  • 5. Creating Nano-scale materials by physically or chemically breaking down larger materials Assembling Nano materials atom- by-atom or molecule-by molecule (self assembling) Approaches in nanotechnology Top-down Approach Bottom-up Approach
  • 6. Nanotechnology: Size and Scale
  • 7. Application Of Nanotechnology Agrochemical Ex: Nanoparticles in pesticides Convergence Nano-Geo-(Bio)-Info technology In food industry Sensing Ex: Detect chemicals or food borne pathogen Safety Packaging Ex: Prevent or respond to spoilage
  • 8. Nano powders - building blocks of Nano materials (particles less than 100 nm in size) Nanoparticles of gold for new catalysts The scale of Nano powders Nano materials Porous metallic ‘Nano cubes’ store large amounts of H2
  • 9. Properties Of Nano materials
  • 10. Optical Property • Due to surface Plasmon resonance • Due to the increased energy level spacing Mechanical Property • Dislocation-free or perfectness as grain diameter deceases from 50-100nm • Some pores or flaw originated from preparation method Elastic Property For grain size<5nm: decreasing E due to number of atoms associated grain boundaries becomes very large
  • 11. Hardness and strength • Increase with (grain diameter)-1/2 (Hall- Patch equation) • since grain boundaries: barrier against dislocation movement • Some NC materials have showed deviation from H-P equation… Ductility and toughness • Increase in coarse grain size materials(d>1um), toughness and ductility increases • NC materials(d<30nm): brittle Superplastic behavior • elongation(tensile deformation) of 100% to >1000% without necking or fracture • Some NC: super plasticity transition temperature is lowered and strain rate increased with the decrease in d, usually for T>0.5Tm
  • 12. Some Other Properties of Nanomaterial High Strength, Hardness, Formability and toughness More Brittle Super Plasticity Magnetic moment can be increased Optical Density can be varied with the diameter Melting point gets reduced on reducing the grain size The Magnetization and coercivity are higher
  • 13. Disadvantages of Nanomaterials
  • 14. Impurities Since nanomaterial are highly reactive ,they inherently interact with impurities as well. In addition, encapsulation of nanoparticles become necessary whey they are synthesized in a solution.
  • 15. It is extremely hard to retain the size of nanoparticles once they are synthesized in a solution. Hence, the nanomaterial have to be encapsulated in a bigger and stable molecule/material. Hence free nanoparticles are hard to be utilized in isolation, and they have to be interacted use via secondary means of exposure. Difficulty in synthesis, isolation and application
  • 16. Instability of particles Retaining the active metal nanoparticles is highly challenging , as the kinetics associated with nanomaterials is rapid.
  • 17. Effect On Human Body Nanoparticles are small enough to be absorbed by the skin and cause irritation and have indicated to be carcinogenic. Breathing in any fine or tiny solid particles can cause irritation in the lungs and can cause lung cancer. Example:- coal workers, quarry workers etc.
  • 18. Some more disadvantages of nanomaterials.. Chemicals in the form of tiny nanoparticles have been shown to spread throughout a crop plant and affect growth and soil fertility Nanosilver particles kill bacteria. But they kill good non- bacterial cells or good bacteria if it is inhaled or ingested. No hard and fast safe disposal policies evolved Nanomaterials are more costly to produce compared to more traditional bulk materials

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