Clay is a naturally occurring material composed
primarily of fine grained minerals, which shows
plasticity through a variable range of water content
and which can be hardened when dried or fired.
Clay deposits are mostly composed of clay
minerals (phyllosilicate minerals) and variable
amount of water trapped in the mineral.
Clay materials have been investigated because of
their importance in agriculture, in ceramics, in
construction and other uses.
STRUCTURE OF CLAY
There are four main groups of clays:
2-Montmorilonite(nanoclay raw material).
Nano clays are minerals which have a high
aspect ratio and with at least one dimension of
the particle in the nanometer range.
The purity and NANO exchange capacity of
the nano-clay are also critical characteristics.
The purity is important in achieving maximum
increases in mechanical properties and
achieving optimum clarity for use in films.
Impurities act as stress concentrators,
resulting in poor impact and tensile properties.
The cation exchange capacity provides the
surface activity necessary for acceptance of
modifiers or surface treatments.
Dissolved in de-ionized water
Stirred using magnetic stirrer
Heated in a furnace at
Experimental procedure :
Nano clays are synthesized by the sol-gel
method while ethanol and some acids are used as
The sol-gel process is a wet-chemical technique
widely used recently in the fields of materials
science and ceramic engineering.
Such methods are used primarily for the
fabrication of materials starting from a chemical
solution which acts as the precursor for an
integrated network (or gel) of either discrete
particles or network clays.
Typical precursors are acetic, nitric, Chloride,
formic and sulphuric acids, which undergo various
forms of reactions.
Clay may form a sol (quick clay) if it is washed
sufficiently to remove the counter ions. Quick clay
may be gelled if enough counter ions are added, so
that the colloidal particles aggregate.
Sol-gel synthesis may be used to prepare
materials with a variety of shapes, such as porous
structures, thin fibers, dense powders and thin
The schematic processes
which show how incoming
molecules can penetrate
through the clay and expand
(a) Dry condition (interlayer),
(b) The incoming molecules
like water molecules wedge
into the interlayer after adding
water or acid and
(c) The cation's are hydrated
which results in repulsive
forces and expanding clay
layer ( Hydration energy).
XRD patterns and AFM images show, the
expansions in clay layers can be due to changes
in elastic modulus of the multilayer's.
It can be intentionally tuned by changing the
multilayer design and that significant porosity is
present in the multilayer even after heating and
The improved mechanical stability of the
nanoclay structures yields to the formation of
strong C–O–C bonds and Si–O–Si bonds between
the two silanes of dense structure.
The characterization of clay synthesized by the
sol – gel method was studied by using XRD and
The samples are cleaned inside the ultrasonic
bath after rinsing and washing in heated acetone
then ethanol the surface cleanliness is checked
with XRD technique.
The nanometer-sized montmorillonite clay
particles can improve surface integrity and
provide advantages in the mechanical and
thermal properties of the composite.
The overall increase in efficiency of this media
is three to four times faster than unfilled polymer
while the durability has more than doubled.
The interaction between nanoclay and
surrounding matrix even though high tensile
strength and modulus were obtained.
Epoxy resin and hardener in the ratio of 5:1
were used to produce nanoclay/epoxy
Organomodified nanoclay particles (SiO2) were
then added into the mixture of epoxy resin and
hardener to form nanoclay/epoxy composites.
All composites with the nanoclay content of 1
wt.%,3 wt.%, 4 wt.% 5 wt.% and 7 wt.% and four
identical samples for each type of composites
The increase of Young’s Modulus of
nanoclay/epoxy samples is dependent on the
amount of nanoclay being added.
The stiffness of the samples with 3 wt.%, 4wt.%
and 5 wt.% of nanoclay increased by 24%, 31%
and 34% respectively.
All the nanoclay/epoxy samples achieved higher
ultimate tensile strength as compared with the
The Young modulus and tensile strength of the
composites increased with increasing the
nanoclay content. The optimal amount of
nanoclay should not exceed 5wt.%.
The increases of Young’s modulus and tensile
strength of a composite sample with 5wt.% were
28% and 25%, respectively.
Further increasing the content of nanoclay
would result in decreasing the mechanical
properties of resultant composites.
The fracture surface of the sample after the test
was then investigated morphologically using SEM
It was found that the samples with 3 wt.% and 4
wt.% of nanoclay formed nanoclay clusters with
uniform size and dispersion.
TEM also retrieved that the addition of
nanoclay can bridge up the voids to avoid the
formation of crack due to the interlocking effect.
Nanoclay clusters with the diameter of 10 nm
enhanced the mechanical interlocking inside the
composites and thus, breaking up the crack
The formation of boundaries between the
nanoclay clusters and epoxy can fine the matrix
grains and further improve the flexural strength
of the composites.
APPLICATION OF NANO CLAY
Clay minerals have long been used in several
applications, ranging from industrial materials to
consumption in health-related products.
The introduction of nanoclay as fillers or additives in
polymers for various desired effects has been of
enormous interest for research and development studies.
An increased consumption is indicated by
clay nanocomposites approaching almost
one-quarter (24 pct) in 2005.
Montmorillonite and nanoclay is useful in
The performance of cosmetics is enhanced by
the use of nanoclay and they allow good color
retention and coverage for nail lacquers, lipsticks
and eye shadows.
Nanoclay as drug vehicle: nanoclays as drug
vehicle for controlled release of drug is one of
the born age area in medicinal application,
nanoclay have great potential as compared to
polymer and carbon nanotubes for drug delivery
Thickening lubricating oils with nanoclay can
produce especially high temperature resistant
The use of nanoclay in wastewater treatment
has become common in industry today.