Introduction to nanoscience

1. Nano Science : An
Expanding Horizon
Let us begin our journey to the world of nano
By
Dr. Anindita Bhattacharya
Assistant Professor
Presidency University, Bangalore

2. Nano Science and Technology
 Nano Science and Technology refers to the science and
technology of matter manipulated at the atomic level.
 Nano≈ Nanometer 10-9 meter

3. Size change in nano level leads to
property change
 There is no example in the history of science where
properties of materials change with size change without
change in chemical composition .
 EXCEPT IN “ NANOSIZE RANGE”

4.  In 1871 Lord Kelvin asked whether melting point of gold
would vary with size.
 After 105 years in 1976 it was observed experimentally
with aid of proper experimental tools.

8. Different nanostructures

9.  A nanomaterial is a structure which is smaller
than 100 nm in at least one dimension.
• 0-D Nanoparticles
• 1-D Nanowires or nanotubes
• 2-D Thin films
• 3-D Porous structures

11. Characteristic dimension
 The dimension refers to characteristic dimension.
 A nano sheet may not have nanometer dimensions along
all axes while the thickness of the sheet is in nanometer,
length and breadth may be larger units.
 A nanowire has diameter in nanometers but length may be
in micrometer.
These nano scale dimensions are characteristic dimensions,
as they decide the properties of the system.

12. TEM PICs of nanoparticles and nanosheets
TEM picture of gold
nanoparticles
Silica nanosheets

13. TEM of nanowire
TEM PIC of silver nanowire
Gold nanorods

14. THANK YOU