Powerpoint on advantages and disadvantages of nano composite materials

1. NANOCOMPOSITE AS A
FLAME RETARDANT
(NANOFLAM)
• In this nanocomposite the nanoparticles can reduce the
flammability of polymers because of the reduction in heat
release rate, the increase in flame-out and their ability to auto-
extinguish.
• It can produce a wide variety of textile coatings which can
promote fire retardation.
• It can be used in different ways of protection via either, a
hydrophobic coating or a thermal barrier coating.
• Nanoflam produces membranes and coatings which are
used in this manufacture.

2. DESCRIBING
NANOCOMPOSITES:
• Nanocomposites may be described as either
immiscible (aggregated), intercalated or
exfoliated (also called delaminated); another
possible description is an end tethered structure

3. IMMISCIBLE
(AGGREGATED)
NANOCOMPOSITE
STRUCTURE:
• An immiscible nanocomposite is a
conventional composite in which the
clay is not separated into layers but
rather only aggregates of clay are
present.

4. INTERCALATED
NANOCOMPOSITE
STRUCTURE:
• Intercalated structures are formed when a
single (or more) extended polymer chain is
intercalated between the layers of clay.
• The result is a well-ordered multilayer structure
of alternating polymeric and inorganic layers,
with a repeat distance between them;
intercalation causes about 2-3nm separation
between the platelets

5. EXFOLIATED
(DELAMINATED)
NANOCOMPOSITE
STRUCTURE:
• Exfoliated (delaminated) structures
are formed when the clay layers are
well separated from one another
and individually dispersed within the
continuous polymer matrix.

6. NANOCOMPOSITE DESCRIPTION CONTINUED
• In an intercalated structure, registry is maintained between the clay layers while registry
is lost in an exfoliated structure, because they have higher phase homogeneity than the
intercalated counterpart, the exfoliated structure is more desirable in enhancing the
properties of the nanocomposites.
• The exfoliated configuration maximizes the polymer-clay interactions making the entire
surface of layers available for the polymer, which should lead to the most significant
changes in mechanical and physical properties.
• However, it is not easy to achieve complete exfoliation of clays and, indeed with few
exceptions, most of the polymer nanocomposites reported were found to have intercalated
nanostructures.

7. OUR 3 INSTRUMENTAL TECHNIQUES CHOSEN:
• Instrumental techniques to characterize nanoflam include Transmission Electron Microscope
(TEM), X-Ray Diffractometer (XRD) and Nuclear magnetic resonance (NMR) spectroscopy:
Complementary to XRD, TEM is the most popularly employed technique to determine
nanocomposite morphology; using TEM can image the nanocomposite structure.
In general, you collect several images at high and low magnification and at several positions
in the nanocomposite sample. Both a low magnification image, to show the global
dispersion of the additives in the polymer, and a higher magnification image, to evaluate
the registry of additives are needed.
1) Transmission Electron Microscope
(TEM):

8. HOW DOES
TEM WORK?
• It uses beams of electrons
which have been
accelerated and pass
through a very thin piece of
specimen, where it interacts
with it and generates a
projection image.
• It gives a higher resolution
image than a light
microscope
Transmission
electron
microscope
Light
microscope

9. EXAMPLE OF TEM:
Figure 1. PS/MMT
(montmorillonite)
nanocomposite TEM
micrographs
a) Shows TEM at low magnification
b) Shows TEM at higher magnifications

10. • It is well known that only materials ordered enough to diffract X-ray can be detected; disordered
materials will show no pattern with the X-ray technique.
• An intercalated nanocomposite results in an increase in basal spacing in the XRD pattern, while
the formation of an exfoliated nanocomposite leads to the complete loss of registry between the
layers and so no peak can be observed.
• A strong peak at lower values of 2θ = intercalated structure
• A broad peak at any 2θ = the possibility of disorder;
this disorder could be caused by exfoliation or it could be a simple composite which is disordered
• However, XRD is insufficient to characterise the nanocomposites structure, SO analytical techniques
must be utilized to confirm the morphology of material and explain the meaning of the XRD signal
2) X-RAY DIFFRACTOMETER (XRD):

11. HOW DOES XRD
WORK?
• XRD works by irradiating a material with
incident X-rays and then measuring the
intensities and scattering angles of the X-rays
that leave the material.
• Once the X-ray beam is focused on the
specimen it is diffracted by the specimen’s
crystalline phases according to Bragg’s law 
A = 2d sinθ
• The Diffracted X-rays intensity is then
measured and as stated in previous slide, the
orientation of the specimen will be determined
by the peak present at the value of the 2θ.
Single-crystal X-ray diffraction

12. EXAMPLE OF XRD:
In this figure we are shown XRD patterns of
Zn2Al-X (X= CO3
2-, Cl-, NO3- and SO4
2-)
Layered double hydroxides (LDHs) washed
with acetone.
In this XRD example we can see that the
XRD patterns for all LDH samples exhibit
the typical patterns of hydrotalcite-like
materials, which is a doubled layered
hydroxide of general formula Mg 6Al 2CO
3(OH).4H2O

13. 3) NUCLEAR MAGNETIC RESONANCE (NMR):
• The interpretation of TEM images tends to be very subjective; the person who has made
the system almost always sees more exfoliation than others may see.
• The NMR technique offers an opportunity to quantify, in a way, the type of dispersion.
• The main objective in solid-state NMR measurement is to connect the measured
longitudinal relaxation times, T1Hs, of proton with the quality of clay dispersion; the
extent and the homogeneity of the dispersion of the silicate layers within the polymer
matrix are very important for determining physical properties.1

14. HOW DOES NMR WORK?
• When molecules are placed in a strong magnetic
field, the nuclei of some atoms will begin to behave
like small magnets.
• The resonant frequencies of the nuclei are then
measured and converted into an NMR spectrum that
displays all of the right frequencies as peaks on a
graph.
• The height of each peak represents the number of
nuclei that resonates at each specific frequency.
This is known as the intensity of signal. The more
resonating nuclei, the higher the intensity.
NMR machine

15. COMPARING THE RATE OF HEAT RELEASE OF NANOCOMPOSITE
FLAME RETARDANTS VS NORMAL FLAME RETARDANTS:
Heat release rate plots for polystyrene, and a polystyrene
nanocomposite containing iron (MMT) and one in which iron is absent
(SMM).
As you can see from the Heat release rate
plot, the polystyrene has the highest heat
release, showing that it is a poor flame
retardant compared to the others shown.
The best is the polystyrene
nanocomposite containing iron (MMT) as
its heat release rate is far lower than
polystyrene.

16. HISTORY OF
FLAME
RETARDANTS
• Halogenated flame retardants (HFRs) have been
used since the 60s mainly because they’re significantly
more compatible with many polymeric materials and
much better at causing charring and reducing smoke
allowing more time for escape.
• Fire retardants used to be compounds such as
Antimony Bromide or compounds containing
Chlorine. Hundreds of brominated and chlorinated
flame retardants have been developed and are being
detected in the environment.2

17. ISSUE WITH THIS:
• Using halogen chemicals can cause
environmental damage by destroying
the ozone layer in the stratosphere. 1
chlorine atom can destroy over 100,000
ozone molecules before it is removed
from the stratosphere!
• This is important to note as the Ozone
can be destroyed more quickly than it is
naturally created.

18. • Other minerals and compounds used as flame retardants include Aluminium Hydroxide,
Magnesium Hydroxide and compounds that have been heavily brominated.
ISSUES WITH THIS:
• The main issue with these certain compounds is that they can be expensive
EXAMPLES OF FLAME RETARDANTS:

19. SYNTHESIS OF NANOFLAM:
The methods of making flame-retardant PLA (polylactic acid) can be mainly divided into two
categories: incorporating inorganic or organic flame-retardant additives into PLA
through melt or solution blending, and copolymerization of reactive comonomers with
PLA. The flame-retardant additives include inorganic fillers (aluminium hydroxide,
hypo-phosphite salts, and expandable graphite) and organic additives (small-molecule
phosphates, oligomers/hyperbranched polymers).3

20. Conclusion:
• Nanocomposites as flame retardants are very beneficial compared to previously used flame
retardants, even though expensive in price they save the destruction of the ozone layer from
harsh halogen chemicals and significantly reduce the heat release rate of a fire which is a lot
more important to think about than just money.
THANK YOU FOR LISTENING TO OUR PRESENATATION ON OUR NANOCOMPOSITE
NANOFLAM, DOES ANYONE HAVE ANY QUESTIONS?
REFERENCES:
1 The Utility of Nanocomposites in Fire Retardancy
Linjiang Wang, Xuejun He, Charles A. Wilkie, Materials (Basel) 2010 Sep; 3(9): 4580–4606. Published online 2010 Sep 3. doi: 10.3390/ma3094580
2Frank L. Dorman, Eric j. Reiner, in Gas Chromatography, 2012, chapter 28.5 Halogenated Flame Retardants
3D.-Y.Wang, in Novel Fire retardant Polymers and Composite Materials, 2017