Presentation on Functionalization of nanoparticles, magnetic nanoparticles, chemical funtionalization, funtionalization of carbon nanotubes and their applications. Introduction about graphite nanoplatelets.

1. By – Deepak rawal
Roll no. – 1508008
Department – B.Sc. (H) Polymer science, 3rd year

2. Introduction
Why functionalization?
Magnetic nanoparticles
Chemical functionalization of nanoparticle
Functionalization of Carbon Nanotubes
Endohedral functionalization
Exohedral functionalization
Applications of nanoparticles
Nanoplatelets

3.  Functionalization is the introduction of organic molecules or polymers on the
surface of the nanoparticle.
 To improve the properties of nanoparticles and to make them biocompatible, it is
necessary to physically or chemically attach certain molecules, or functional
groups, to their surface. This process is called functionalization.

4.  The surface coating of nanoparticles determines many of their physical and
chemical properties, notably stability, solubility, and targeting. A coating that is
multivalent or polymeric confers high stability.

5.  There are limitations in the applications of nanomaterials because of their
restricted behaviour in different solvents.
 Surface modifications of nanomaterials help to tune their properties to suit
different applications in the field of nanotechnology, because surface properties
determine the interaction among the components, as well as the solubility and
agglomeration behaviour in different solvents.
 Surface modification can be used to prevent aggregation, improve stability in
suspensions, and enhance the compatibility of nanoparticles with solid matrices or
biological environments. It also provides means for further grafting or conjugating
additional functional molecules.

6.  Magnetic nanoparticles are a class of nanoparticle that can be manipulated using
magnetic fields.
 Such particles commonly consist of two components, a magnetic material, often
iron, nickel and cobalt, and a chemical component that has functionality.
Cobalt nanoparticle with graphene shell
(The individual graphene layers are
visible)

7.  Nanomaterials have been widely used in the manufacturing of biosensors, labels
and magnetic storage devices because they exhibit electrical, optical and magnetic
properties distinct from their bulk counterparts.
 Magnetic particles are especially important because of their applications in
various areas.
 They have been investigated for their use in biological labeling, magnetic
resonance imaging (MRI), targeted drug carriers for cancer therapy, sensing,
magnetic separation, and ferrofluids in heat transfer, dampers and actuators.

8. The response of magnetic nanoparticles to an external field is an appealing feature
for their uses in drug delivery and biological separation, such as cell sorting.

9.  Magnetic nanoparticles exposed to alternating magnetic fields can produce
thermal energy and enable effective hyperthermia therapy.
 The spin carried in magnetic nanoparticles can respond to the surrounding
microenvironments and be exploited in MRI

10. By doing chemical surface modification or attaching functional groups, a nanoparticle can be
made Hydrophilic, hydrophobic, conductive or anticorrosive in nature.

11.  TWO TYPES OF FUNCTIONALIZATION:
Endohedral functionalization
Exohedral functionalization

12.  Here CNTs are treated by filling their inner empty cavity with different functional
groups or nanoparticles

13.  It involves grafting of molecules on the outer surface of nanotubes
 Several approaches have been developed and include defect functionalization,
covalent functionalization and noncovalent functionalization with surfactants or
polymers
 The different types of exohedral functionalization can be classified via the nature
of the interactions between the surface of carbon nanotubes and the functional
groups or polymer chains
 These interactions can rely upon covalent or non-covalent bonds.

14.  Functionalization possibilities for CNTs:
(A) defect functionalization
(B) covalent sidewall functionalization
(C) noncovalent functionalization with surfactants
(D) polymer wrapping

15.  The noncovalent interaction is based on van der waal forces or π-π stacking and it
is controlled by thermodynamics
 The great advantage of this type of functionalization relies upon the possibility of
attaching various groups without disturbing the π electronic system of the rolled
graphene sheets of CNTs

16.  Two major groups of chemical functionalization of CNTs via covalent attachment
can be distinguished,
1. the “end and defect side” functionalization
2. sidewall functionalization
 End and defect-side functionalization:
The functionalization via “end and defect-side” chemistry consists to graft
functional group directly on the already existing defects in the structure of CNTs

17. Typical defects in a SWCNT
Covalent addition of carbene
group on CNT surface

18.  Sidewall functionalization:
It involves grafting of chemical groups through reactions onto the π-conjugated skeleton of
CNTs
The reactivity of CNT sidewalls remains low and sidewall-functionalization is only
successful if a highly reactive reagent is used

19.  In Hydrophobic coatings
Mainly used in smartphones and automobiles coatings

20.  In anti-corrosive coatings
Development of nano porous reservoir for storing of corrosion inhibitors on the
metal-coating interface
Nanomaterials mostly used in coating system: SiO2, TiO2, ZnO, Al2O3, Fe2O3,
nano-aluminum, nano-titanium

21.  In UV-Blocking Coatings
Nanoparticles of ZnO, TiO2 have excellent photo- and thermal stability

22.  Graphite Nano-platelets (GnP) are nanoparticles made from graphite. These
nanoparticles consist of small stacks of graphene that are 1 to 15 nanometers
thick, with diameters ranging from sub-micrometre to 100 micrometres.
 The platelet shape, offers Graphite Nanoplatelets edge that are easier to modify
chemically for enhanced dispersion in polymers.

23.  Hydrogen or covalent bonding capability can be added through functionalization
at sites on the edges of the platelets.

24.  Enhanced barrier properties and improved mechanical properties (stiffness,
strength, and surface hardness) can be achieved with the graphene nanoplatelets
due to their unique size and morphology.
 The nanoplatelets are also excellent excellent electrical and thermal conductors as
a result of their pure graphitic composition.
 Composite materials made with polymers, like plastics, nylon, or rubber, can be
made electrically or thermally conductive with the addition of small amounts of
Graphite Nanoplatelets. These nanoparticles can change the fundamental
properties of plastics, enabling them to perform more like metals with metallic
properties.

25.  Because of their unique nanoscale size, shape, and material composition, graphene
nanoplatelets can be used to improve the properties of a wide range of polymeric
materials, including thermoplastic and thermoset composites, natural or synthetic
rubber, thermoplastic elastomers, adhesives, paints and coatings.
 These properties includes:
1. Increase thermal conductivity and stability
2. Increase electrical conductivity
3. Improve barrier properties
4. Reduce component mass while maintaining or improving properties
5. Increase stiffness
6. Increase toughness (impact strength)
7. Improve appearance, including scratch and abrasion resistance
8. Increase flame retardance

26.  The multifunctional property improvements offered by graphene nanoplatelets make
them ideal additives for applications where several property improvements are
required.
1. Significant processing or material cost savings can be achieved.
2. Achieve effective electrical conductivity with improved stiffness and toughness in
cost-sensitive applications
3. Improve the cross-fiber electrical conductivity and thermal conductivity of carbon-
fiber composites
4. Produce lower cost nanotube-containing conductive polymers with improved barrier
properties
5. Render fiberglass electrically conductive without requiring any changes in
processing or fabrication procedures
6. Improve barrier properties while also enhancing stiffness, strength, and scratch-
resistance without reducing toughness