1. GANDHINAGAR INSTITUTE OF
TECHONOLOGY(012)
SUBJECT : Physics (2110011)
Active Learning Assignment on the topic of
“ Introduction to Nano-materials “
BE Mechanical
Prepared By: Yash Pandya
Guided By :
2. CONTAIN
Introduction
Classification of Synthesis Method
Techniques Used in Synthesis Method
Properties & Applications of Nano-Materials
Disadvantages of Nano-Materials
References
3. What are Nano-Materials?
Nano materials are defined as a set of substances where at least one
dimension is less than approximately 100 nanometers.
A nanometer is one millionth of a millimeter -approximately 100,000
times smaller than the diameter of a human hair.
1D film
Graphene
2D nanowire,
nanotube
3D
nanoparticle
4. Examples of Nanomaterials
Nanomaterials (gold, carbon, metals, meta oxides and alloys) with
variety shapes are depicted in Figure.
AU Nanoparticle Buckminsterfullerene FePt nanosphere
Titanium nanoflower Silver nanocubes SnO2 nanoflower
5. Classification of Synthesis Method
The methods for the synthesis are classified into two processes:
1. Top-down process &
2. Bottom-up process.
The top-down process involves, the breaking down of a large piece of a bulk
materials to generate the required smaller and smaller nanostructured
material from the bulk materials.
The bottom-up process involves the process of building up of the atom into a
larger nanostructured material.The bottem-up approach is a powerful approach of
creating identical structures with atomic precision.
6. Techniques Used in Synthesis Method
Various techniques are adopted for the synthesis of nano-materials based
on the above two process…
For Top-down process : 1. Milling
2. Lithographics
3. Machining
For Bottom-up process : 1. Plasma assisted deposition process.
2. Vapour deposition methods.
3. Liquid phase processes.
4. Molecular Beam Epitaxy.
5. Laser synthesis
7. PROPERTIES
The nano-materials have high strength, hardness, formability and
toughness.
Its magnetic moment can be increased by decreasing the particle size.
Opticle density can be varied with the diameter.
The melting point gets reduced on reducing the grain size.
The magnetisation is higher.
8. APPLICATIONS
Amorphous silica fume (nano-silica) in Ultra
High Performance Concrete – this silica is
normally thought to have the same human
risk factors as non‐nano non‐toxic silica dust.
Nano platinum or palladium in vehicle
catalytic converters - higher surface area to
volume of particle gives increased reactivity
and therefore increased efficiency.
Crystalline silica fume is used as an additive
in paints or coatings, giving e.g. self-
cleaning characteristics – it has a needle-like
structure and sharp edges so is very toxic and
is known to cause silicosis upon occupational
exposure.
10. Disadvantages
Impurity
Difficulity in synthesis, isolation & application
Instability of the particles
Biologically harmful
More costly to produce compared to bulk materials
Recycling and disposal