To analyze a flame retardant nanocomposite, parameters such as heat release rate, carbon monoxide production, and smoke production should be considered by comparing materials with and without nanocomposites. Transmission electron microscopy, X-ray diffractometry, and nuclear magnetic resonance could be used to characterize the nanocomposites. Transmission electron microscopy provides information on particle size, distribution, and morphology while X-ray diffractometry indicates structure and interactions between layers. Nuclear magnetic resonance analyzes polymer-filler interfaces and restricted chain motions at the interface.

1. Nanoflam (nanocomposite as a flame retardant) product analysis
What analysis would be done?
To properly analyse a flame retardant nanocomposite, there are many parameters we
should consider; heat release rate, peak of heat release rate, rate of carbon monoxide
production, smoke production rate, total mass loss rate, time of ignition and total peak of
heat release rate. Comparison between materials without nanocomposite incorporation and
materials which do, using these parameters should outline how useful these
nanocomposites are. The main goal for a nanocomposite as a flame retardant is to improve
the parameters listed without causing deterioration of the mechanical properties to the
polymer matrix.1 There are different morphologies concerning nanoparticles and they can
be described In three ways, aggregated, intercalated and exfoliated. The exfoliated
structure is much better in enhancing the properties of the nanocomposites compared to
the other two counterparts. The exfoliated configuration is of particular interest because it
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.2
One study showed that the peak heat release rate was reduced by 40% with the addition of
an exfoliated nano-composite as opposed to without the nano-composite.3
Figure 1 – shows the three different morphologies mentioned.
Also, there are techniques we can use to analyse the nanocomposite itself to display its
physical properties which will be listed later on.
Which techniques would you use?
 Transmission electron microscope
A transmission electron microscope uses an accelerated, concentrated beam of
electrons which is shot at a very thin specimen. Once the electrons have gone
through the sample, they are detected and this produces an image. These images are
produced with different shades according to the different densities of the different
parts of the specimen being examined. The electrons are produced by an electron
gun facing the specimen and uses an electromagnetic lens which focuses the

2. electrons into a very fine beam. Transmission electron microscopes are able to
produce much higher resolution images as they are not limited by wavelength such
as a light microscope. Some of the main advantages of TEM include; TEMs offer the
most powerful magnification, potentially over one million times, TEM’s provide
information on element and compound structure and images are high-quality and
detailed. However some disadvantages are the cost, training is required for someone
to operate and images produced are black and white.4
 X-ray diffractometer
XRD irradiates a material with incident X-rays, then it measures the intensities and
the scattering angles of the x-rays that are given off by interacting with the sample.
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). They are diffracted because
the interaction between the X-rays and the atoms’ electrons. Using the measured
intensities, the orientation will be determined by the peak present at the value 2θ.
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. Some advantages of XRD are; it is fast and a powerful
technique for identifying structures, the sample sizes can be small and resulting data
is relatively straight forward. Some disadvantages are that the sample should be
homogenous and samples are best to be crushed into a powder.5
 Nuclear magnetic resonance
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 correct
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. Advantages are that it is
not invasive and the radiation is there is not much ionizing radiation. However some
disadvantages are that it may be too sensitive, and it is extremely expensive to firstly
buy and then keep it running.6

3. What information would they provide?
Some of the information that the technique TEM could provide include grain lattice type,
crystal structure, size, size distribution and homogeneity, dispersion, and chemical and
physical property of phases such as number, morphology, and structure of the phases at
nano level. 7
Figure 2 – Shows images of cross sections taken by TEM of PLA composites.
XRD can be used as another non-destructive technique and can provide
detailed information about the crystallographic structure, chemical composition, and
physical properties of materials.
One of the major advantages of NMR (solid state) is to allow the analysis of polymer–filler
interfaces due to the sensitivity of the NMR spectra and the relaxation parameters to the
local and segmental molecular motions of polymer chains. Polymer–filler interactions
normally contribute to the formation of an adsorption layer in which chain motions are
more restricted than those in the bulk, and solid-state NMR has been shown to be able to
differentiate the polymer behaviour in the interfacial region from that in the bulk.8

4. 1 https://www.intechopen.com/books/flame-retardants/flame-retardant-polymer-
nanocomposites-and-interfaces
2 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5445768/#B2-materials-03-04580
3 https://pubs.rsc.org/en/content/articlelanding/2017/nj/c7nj02566a#!divAbstract
4 https://www.microscopemaster.com/transmission-electron-microscope.html
5 https://www.scimed.co.uk/education/what-is-x-ray-diffraction-xrd/
6 https://academic.oup.com/ilarjournal/article/42/3/189/778963
7 https://www.researchgate.net/figure/A-ring-diffraction-pattern-from-a-polycrystalline-
gold-specimen_fig5_267104201
8 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5445768/#B2-materials-03-04580