Nanomaterials have at least one dimension in the nano range2 which results in materials that
have a larger surface area-to-volume ratio. This characteristic makes the surface of
nanomaterials highly reactive, which causes changes in many fundamental properties such as
thermal and electrical conductivity, melting temperatures, mechanical strength and even color of
the substance. Altering material properties at nanoscale through nanotechnology has led
scientists to develop nanocomposites – a new class of materials with fascinating properties
ready to be integrated with various industrial applications and with the potential to impact the
future direction of the world. In this article we take a dive into the miniscule world of
nanocomposites – their classifications, properties and industrial applications, to show the
potential benefits nanocomposites can bring, in terms of innovative solutions and economic
advantage. The American physicist Richard Feynman in his famous Caltech speech said that
“There is plenty of space at the bottom”, encapsulating the advancement of nanotechnology and
paving the way for the development of robust and versatile nanocomposite materials.
What are Nanocomposites?
Nanocomposites are made by mixing a conventional bulk material with one or more types of
materials. This combination is what gives the nanocomposite outstanding properties. The
nanomaterials that are added to the bulk matrix can be in various forms – nanotubes,
nanoparticles or any other nanostructural form. Furthermore, nanocomposites are categorized
according to various classifications based on the following1:
- Matrix type
- Reinforcement type
- Chemical nature
Out of the above categorizations, nanocomposite classification according to the matrix type is
explored in detail in this article. Based on the matrix type, nanocomposites are divided into the
following groups1:
● Polymer Matrix Nanocomposites (PMNC)
● Metal Matrix Nanocomposites (MMNC)
● Ceramic Matrix Nanocomposites (CMNC)
Polymer Matrix Nanocomposites
As the name suggests, polymer matrix nanocomposites (PMNC) are constructed using a
polymer as the matrix3. A material which has at least one dimension in the nanoscale, often
called a nanofiller, is then dispersed into the polymer matrix. This additional nanomaterial
dispersion helps to elevate the mechanical, electrical and thermal properties, resulting in a
versatile nanocomposite.
To produce polymer matrix nanocomposites, the polymer is often based in a medium which
dissolves the polymer while swelling the nanomaterial, facilitating the polymers to form a
structure around the nanomaterials. Polymer matrix nanocomposites possess unique
fundamental properties such as mechanical, thermal, electrical and optical properties while
displaying the characteristic lightweight and ductile nature of polymers.
Metal Matrix Nanocomposites
Metal matrix nanocomposites (MMNC) are produced by using a ductile metal or alloy as the
matrix, and then reinforcing a nanomaterial into the matrix4. Metal matrix nanocomposites are
often constructed using a self assembly technique. In this technique, individual units of
nanomaterial are allowed to self-assemble into a specific structure within the metal matrix.
MMNCs display toughness and high strength, high service temperature capacities and flexibility
of design. Due to these characteristics, they are highly sought after in the aerospace and
automobile industries.
Ceramic Matrix Nanocomposites
In ceramic matrix nanocomposites (CMNC), ceramic fibers are reinforced into a ceramic matrix.
The method of pyrolysis, essentially a heat treatment method, is also used to prepare ceramic
nanocomposites. In this method, a ceramic solution is converted into a gel-like substance, and
is then mixed with the desired nanomaterial. CMNCs are tough due to the fibers being
interlaced in the matrix and known for the remarkable durability and high levels of failure
resistance.
Bionanocomposites – A rising star
Apart from the above mentioned main matrix classifications, In the recent past
bionanocomposites have gained the attention of researchers and sustainability enthusiasts5.
Bionanocomposites are prepared by using bio polymers such as Polylactic Acid (PLA) and
Polyhydroxyalkanoates (PHA) and by using synthetic or inorganic nano fillers.
Bionanocomposites can also refer to materials made from renewable nanoparticles such as
microbial fuel cells6. These materials display a range of properties such as thermal stability,
solubility in water, biocompatibility, and biodegradability, making them popular as a type of
hybrid green materials.
Applications of nanocomposites
As iterated above, nanomaterials have amazing mechanical, thermal and electrical properties.
They are a hybrid generation of composite materials that are multifunctional.
The use of nanocomposites are evident in a wide range of applications including tech devices,
medical applications, constructions, transportation, water purification and many more. For
instance, polymer nanocomposites are used to construct electrode materials for new types of
supercapacitors. As a result of the advanced properties of the polymer nanocomposite, the
supercapacitor electrode materials display flexibility and adaptability into many shapes and
sizes, making it highly suitable for wearable electronics. Further, polymers blended with
piezoelectric nanofillers are also used for energy storage and harvesting7.
PMNCs are also used in food grade packaging material and other medical applications.
Polycarbonates with nanomaterial additives have displayed excellent antibacterial activity,
making it a suitable material for commercial kitchens, surfaces in hospitals or any public
locations with risks of bacterial contamination. Some of the characteristics that make
nanocomposites suitable for food packaging are due to barrier properties, thermal properties,
biodegradation and specially the ability to kill or inactivate microorganisms due to high surface
reactivity.
Looking at the diverse range of environmental and industrial applications of nanocomposites8,
Improved properties such as higher photocatalytic activity, antimicrobial activity, membrane
permeability and thermal stability has caused nanocomposites to receive great attention in
water treatment, remediation as well as disinfection. Moreover, the adsorption qualities shown
by nanocomposites make them ideal for metal ion removal, which is an essential requirement
for environmental protection and health. In addition, nanocomposites exhibit heaps of
advantages to the rubber industry. Improving the rubber vulcanization process and reducing the
curing time can be significantly achieved by adding modified graphite into natural rubber
composites. These rubber composites display notable thermal conductivity, thereby saving
energy and in turn reducing operational costs. Similarly, nanocomposites are also used in
cosmetics, healthcare and pharmaceutical products, through incorporation into aqueous or
cream bases.
However, the more advanced uses of nanocomposites are attributed to the electromagnetic
shielding and aerospace applications. Nanocomposites with conductive nanofillers such as
metal, magnetic and carbon nanomaterial are used to shield spaces from the electromagnetic
radiation devices which can otherwise disrupt equipment usage in many fields such as medical,
aerospace and military. As exemplified above, nanocomposites are becoming an essential and
integral part of many fields and applications. Due to its potential as a key component, research
scopes on nanotechnology are becoming broader and as innovation advances , more
breakthrough technology on nanoscale are bound to be deployed overtime.
JKR’s work with Nanocomposites
Small things make big changes, especially at the bottom of the scale. At JKR, we are
constantly exploring possibilities of innovation through nanotechnology to contribute to society
at a higher level. Our work in the nano field such as collagen-graphene-polymer composites,
antibacterial nanocomposites and nano additives, and rubber composites are a testament of our
dedication to a better future. With strategic collaborations and partnerships with a multitude of
local and global stakeholders we aspire to change the world for the better, starting with one
nano step at a time.
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