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Transcript of Hmmv jalandhar presented
DESIGNING NANOMATERIALS: NOVEL
APPROACHES
SHRIRAM INSTITUTE FOR INDUSTRIAL RESEARCH19, UNIVERSITY ROAD, DELHI-110 007
Email : [email protected] Website : www.shriraminstitute.org
Presented by :Dr. R.K. KHANDAL
OUTLINE
Scope
Opportunities
Challenges
Nanomaterials
SRI & Novel Nanomaterials
Classification
Size Effects
Shape Effects
Approaches
Novel Architecture
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
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
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
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
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
NANOSCIENCE TO NANOTECHNOLOGY
NANOSCIENCE NANOTECHNOLOGYBiology
Chemistry
Physics
Value Addition
Performance
Diversification
Measure of success of science and technology is to manufacture and commercialize!
OPPORTUNITIES: NANOTECHNOLOGY
N
A
N
O
S
C
I
E
N
C
E
Carbon
Nanotube
Nanowire
NANOTECHNOLOGY
Carbon nanotube on plastics
Array of Carbon nanotube-devices
TiO2
Sunscreens
CoatingsNano-TiO2
OPPORTUNITIES: NANOMATERIALS FOR INDUSTRIES
NANOMATERIALS
Electronics
Chemicals Energy
Transportation
Medical/Biology Materials
Water
PurificationDesalination
Agriculture
FertilizersPackagingCoatings
Light weightEfficiency
ProsthesisDrug deliveryDiagnosis
CompositesCoatingsConstruction
Data storage High speed devices
Catalysts Fuel CellsBatteries
Nanotechnology has revolutionized various industries; only solution for the emerging needs
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
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 1Discrete
Class 2Surface
Class 3Bulk0-D
d 100 nm
1-D
d 100 nm
2-D
d 100 nmDim
ensi
onal
ity
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
NANOMATERIALS: SIZE DEPENDENCE
Particle size (nm)
Me
ltin
g p
oin
t (K
)
Particle size (nm)
Su
rfa
ce T
ens
ion
(m
N/m
)
Particle size(µm)(nm)
Str
en
gth
Die
lec
tric
C
on
sta
nt
Particle size (nm)100 1000
Bulk
Particle size affects the properties & thus overall behavior of the material
Au Au
AlPbTiO3
NANOMATERIALS : SHAPE DEPENDENT
Sphere
Cylinder Cube
Dimension (nm)
Su
rfa
ce/V
olu
me
(nm
-1)
Nanoscale materials have extremely high surface to volume ratios as compared to larger scale materials
Sphere: S:V = 3 : rCube : S:V = 6 : lCylinder: S:V = 2 : r
r = radiusl = length
DESIGNING OF NANOMATERIALS: APPROACHES
Assembled from nano building blocks
From bulk
Control of size is dependent on end-use applications
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]
Designing of Nanomaterials: DendrimersLinear 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.
DESIGNING OF NANOMATERIALS: ENCAPSULATION
TiO2 TiO2
-
-
-
-
-
-
TiO2
TiO2
-
-
-
-
-
-
MonomerPolymer
Surfactant
-
-Radical
Polymerization
Latex Fe2O3-Particles
Fe2O3-ParticlesLatex 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.
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.
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
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
SRI’S EXPERIENCE
SRI has developed nanomaterials for :
Optical applications
Effluent treatment
23232323232323
LOW REFRACTIVE INDEX MATERIALS
The refractive index of low refractive index materials increases from 1.49 to 1.66.
1 . 4 1
1 . 4 7
1 . 5 3
1 . 5 9
1 . 6 5
1 . 7 1
0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0
% o f a d d i t i v e
Ref
ract
ive
ind
ex
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 30Metal salt (% by wt)
Ref
ract
ive
Ind
ex
Barium Hydroxide Lead Monoxide Lanthanum Oxide
EFFECT OF DISPERSION OF METAL SALTS ON THE REFRACTIVE INDEX OF ACRYLIC ACID
252525252525
Effect of metal on refractive index
In-situ formation of nanoparticles of TiThe 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
Re
fra
cti
ve
Ind
ex
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
ZnOCdS
WO3
Band gap Energy
EMS()
TiO2 = 3.20 eV
ZnO = 3.35 eV
WO3 = 2.80 eV
CdS = 2.42 eV
Semiconductors are the most ideal and preferred materials.
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
Inte
nsi
ty(a
.u.)
Position (2 Theta)20 30 40 50 60 70 80
External
In-Situ method
TiO2 market procured
TiO2 (Reference)
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-Situ Doped External TiO2
THANK YOU