1. DESIGNING NANOMATERIALS:
NOVEL APPROACHES
SHRIRAM INSTITUTE FOR INDUSTRIAL RESEARCH
19, UNIVERSITY ROAD, DELHI-110 007
Email : sridlhi@vsnl.com Website : www.shriraminstitute.org
Presented by :
Dr. R.K. KHANDAL

2. OUTLINE
Scope
Opportunities
Challenges
Nanomaterials
SRI & Novel Nanomaterials
 Classification
 Size Effects
 Shape Effects
 Approaches
 Novel Architecture

3. Nanomaterials:
Materials consisting of particles of the size of
nanometer
Volume = Surface Area * Thickness
 For a given volume:
 Surface area Thickness
 More atoms at surface than in the interior
 Extraordinary activity
SCOPE: DEFINITION

4. SCOPE : DOMAIN
Keywords Domain
Particle size Distribution in the
continuous phase
Modification of surfaces Interfacial tension
Surfaces Interfaces
Rising volume fraction Homogeneity of phases
of dispersing phase
 Domain of Nanotechnology: Multi-phase systems
 Liquid : Liquid
 Solid : Liquid
 Surfaces and interfaces involving different phases
 Gas : Liquid
 Gas : Solid

5. Systems Process
Emulsion Macro Micro
Dispersion Coarse Fine
Solution Colloid
SCOPE: PROCESS
A process to create a continuous dispersed phase as fine
as possible for homogeneity with the dispersing phase
(Liquid / Liquid; Gas/Liquid)
(Solid / Liquid)
(Solid / Liquid; Liquid/Liquid)
Solubilization

6. SCOPE : DIMENSIONS
What Happens Dimensions
 Particle size More from less
 Surface area Enhanced coverage
 Activity Novel products
 Efficiency Improved performance
per unit mass
 Maximum possible benefits from minimum possible inputs
 Effecting changes through and at atomic scale

7. NANOSCIENCE TO NANOTECHNOLOGY“MACRO TO
NANO”
MATERIALS
Copper
Macro
PROPERTIES
Nano
Opaque Transparent
Platinum Catalyst
Aluminium Stable Combustible
Inert
Gold Inert Catalyst
 Unique properties at the nanoscale are the driving force for
exploitation of nanomaterials

8. NANOSCIENCE TO NANOTECHNOLOGY
NANOSCIENCE NANOTECHNOLOGYBiology
Chemistry
Physics
Value
Addition
Performance
Diversification
 Measure of success of science and technology is to manufacture
and commercialize!

9. OPPORTUNITIES: NANOTECHNOLOGY
N
A
N
O
S
C
I
E
N
C
E
Carbon
Nanotube
Nanowire
N
A
N
O
T
E
C
H
N
O
L
O
G
Y
Carbon nanotube on plastics
Array of Carbon nanotube-devices
TiO2
Sunscreens
Coatings
Nano-TiO2

10. OPPORTUNITIES: NANOMATERIALS FOR INDUSTRIES
NANOMATERIALS
Electronics
Chemicals Energy
Transportation
Medical/Biology Materials
Water
Purification
Desalination
Agriculture
Fertilizers
Packaging
Coatings
Light weight
Efficiency
Prosthesis
Drug delivery
Diagnosis
Composites
Coatings
Construction
Data storage
High speed
devices
Catalysts Fuel Cells
Batteries
Nanotechnology has revolutionized various industries; only solution for
the emerging needs

11. Process of making Nanomaterials
Process steps Inputs
Macro
Micro
Nano
CHALLENGES: PROCESS TECHNOLOGY
Challenge: To have a process that can convert macro materials
into nano materials spontaneously & with minimum efforts
Energy
Bulk
Sugar cube
Nano
Dissolved sugar/salt
Bulk
Output
Salt

12. NANOMATERIALS:CLASSIFICATION
Nanoparticles
(Smoke, diesel, fumes)
Nanocrystalline
Materials Nanoparticle
composites
Nanocrystalline
films
Nanorods tubes
(Carbon nano tubes) Inter connects
Multi layer structure
Nano Films Foils
Nantube, reinforced
composites
Surface layers
Class 1
Discrete
Class 2
Surface
Class 3
Bulk0-D
d≤ 100 nm
1-D
d≤ 100 nm
2-D
d ≤ 100 nm
Dimensionality
Multi layer structure
Nanowires &
Nanotubes Multi layers
3-D
3-D nanomaterials are nanocomposites formed of two or more materials with
very distinctive properties, act synergistically to create unique properties that
cannot be achieved by single materials

13. NANOMATERIALS: SIZE DEPENDENCE
Particle size (nm)
Meltingpoint(K)
Particle size (nm)
SurfaceTension
(mN/m)
Particle size
(µm)(nm)
Strength
Dielectric
Constant
Particle size (nm)
100 1000
Bulk
Particle size affects the properties & thus overall behavior of the
material
Au
Au
Al
PbTiO3

14. NANOMATERIALS : SHAPE DEPENDENT
Sphere
Cylinder Cube
Dimension (nm)
Surface/Volume(nm-1
)
Nanoscale materials have extremely high surface to volume ratios
as compared to larger scale materials
Sphere: S:V = 3 : r
Cube : S:V = 6 : l
Cylinder: S:V = 2 : r
r = radius
l = length

15. DESIGNING OF NANOMATERIALS: APPROACHES
Assembled
from nano
building blocks
From bulk
 Control of size is dependent on end-use applications

16. DESIGNING OF NANOMATERIALS :SPHERES AND RODS
Ag(I) or Au(III) salt + NaBH4
More Seeds
+ metal salt + ascorbic acid + CTAB
Less Seeds
+ metal salt + ascorbic acid + CTAB
Seed mediated growth is a good approach for the preparation of
nanorods and nanowires of varying aspect ratios.
Few seeds Longer rods
Seeds
(Stabilizing agent)
(Stabilizing agent)
[H]

17. Designing of Nanomaterials: Dendrimers
Linear Branched Cross-linked Dendritic
Flexible coil
Rigid rod
Cyclic (closed
linear)
Polyrotaxane
Random short branches
Random long branches
Regular comb branches
Regular star branches
Lightly cross linked
Densely cross linked
Interpenetrating
networks
Hyper branched
Ideal dendron
Dendrimer
X
 New types of nanomaterials (nanocomposites) with unusual architecture are
created by highly branched polymers.
 Dendrimers have characteristic features of both macromolecules and the
nanoparticles: Dendrimers help in controlling the particle size.

18. DESIGNING OF NANOMATERIALS: ENCAPSULATION
TiO2 TiO2
-
-
-
-
-
-
TiO2
TiO2
-
-
-
-
-
-
MonomerPolymer
Surfactant
-
-Radical
Polymerization
Latex Fe2O3-Particles
Fe2O3-Particles
Latex
bead
Pre-treatment
Polymerization
Copolymer
layer
Encapsulated particle
Amphiphilic
molecule
Monomer
Polymer encapsulated nanomaterials are used for targeted delivery of
substances such as drugs.
Dimensions of encapsulated substance is tens of nanometers and of
the stabilizing shell is a few hundred micrometers.

19. Designing of Nanomaterials: Optical
Incident Light
Transmitted light (Spectral
luminous gain, switching,
fluorescence, etc.
Optically functional particles
Coating or fibers of the matrix
formed
 Metal ions can be introduced into polymeric fibers to produce
colored light guides.
 Polymer based nanocomposites containing well-dispersed
inorganic particles can exhibit semiconducting properties,
quantum dot effects, non-linear optical properties and extremely
low or high refractive index.

20. DESIGNING OF NANOMATERIALS : MAGNETIC MATERIALS
Isolated
nanoparticles
Nano particles
Ultrafine Nanoparticles core
shell morphology in the matrix
Small magnetic
nanoparticles embedded in
a chemically dissimilar
matrix
Small particles dispersed
in nanocrystalline matrix Magnetic property corer with
polymer coating
The characteristics of magnetic matrices depend on diversity of
interconnected factors
< 1 nm:Non-magnetic ~ 1-10 nm:Super paramagnetic >10 nm: Ferromagnetic
Ex. Mn,Co,Fe &Ni
3M2O3.5Fe2O3
Ni0.5Zn0.4Cu0.1Fe2O3

21. DESIGNING OF NANOMATERIALS: ELECTRICAL MATERIALS
Matrix
 Conductivity of nanoparticles is higher than for micron size particles
 Nanoparticles-polymer interactions influences electro-physical properties
 Size & form of nanoparticles Magnetic characteristics
 Conductivity can exist in every single metal nanoparticle
Structures of composites
Statistical
Layered
Chain
Globular
Examples: Ag,Ni,Cu,Zn

22. SRI’S EXPERIENCE
SRI has developed nanomaterials for :
 Optical applications
 Effluent treatment

23. 23232323232323
LOW REFRACTIVE INDEX MATERIALS
 The refractive index of low refractive index materials
increases from 1.49 to 1.66.
1.41
1.47
1.53
1.59
1.65
1.71
0 10 20 30 40 50 60 70 80 90 100
% of additive
Refractiveindex

24. 24242424
Refractive index increases with increase in percentage of
metal salt.
1.41
1.42
1.43
1.44
1.45
1.46
1.47
1.48
0 5 10 15 20 25 30
Metal salt (% by wt)
RefractiveIndex
Barium Hydroxide Lead Monoxide Lanthanum Oxide
EFFECT OF DISPERSION OF METAL SALTS ON THE
REFRACTIVE INDEX OF ACRYLIC ACID

25. 252525252525
Effect of metal on refractive index
 In-situ formation of nanoparticles of Ti
The refractive index of the polymer increases from 1.45 to
1.53
1.44
1.46
1.48
1.5
1.52
1.54
0 2 4 6
% Ti
RefractiveIndex

26. MATERIALS FOR ENERGY CONVERSION:
SEMICONDUCTORS
Challenge is maneuver the band gap:make it sensitive to
visible light.
6.3 eV 3.15 eV 1.58 eV
U.V
200 nm 400 nm 800 nm
Visible
TiO2
ZnO
CdS
WO3
Band gap
Energy
EMS(λ)
TiO2 = 3.20 eV
ZnO = 3.35 eV
WO3 = 2.80 eV
CdS = 2.42 eV
Semiconductors are the most ideal and preferred materials.

27. XRD : DOPED TiO2
 XRD analysis confirms the doping of TiO2
 Change in lattice parameter ‘a’ & ‘c’ of TiO2,confirms the
incorporation of Cd2+
in Ti4+
Influence TiO2 Doped TiO2 Doped TiO2
factor (In-situ) (External)
a/nm 3.0301 3.3184 3.3558
c/nm 9.5726 10.0136 11.2138
Intensity(a.u.)
Position (2 Theta)
20 30 40 50 60 70 80
External
In-Situ method
TiO2 market
procured
TiO2 (Reference)

28. PARTICLE SIZE ANALYSIS : DOPED TIO2
A particle size of 80 - 87 nm of the doped mixture has been
achieved by In-situ methods
Doped In-SituDoped ExternalTiO2

29. THANK YOU