A year ago IsraCast reported
on the development of the first commercial nano-based
lubricant which was developed by the Israeli
company ApNano materials. A year later we find
ApNano working also on a wholly different application
of their technology - shielding and protection.
In recent research lead by Prof. Yan Qiu Zhu
of the School of Mechanical, Materials and Manufacturing
Engineering at the University of Nottingham,
England, a sample of the ApNano material was
subjected to severe shocks generated by a steel
projectile traveling at velocities of up to 1.5
km/second. The material withstood the shock pressures
generated by the impacts of up to 250 tons per
square centimeter. This is approximately equivalent
to dropping four diesel locomotives onto an area
the size of one's fingernail. During the test
the material proved to be so strong that after
the impact the samples remained essentially identical
compared to the original material. Additionally,
a recent study by Prof. J. M. Martin from Ecole
Central de Lyon in France tested the new material
under isostatic pressure and found it to be stable
up to at least 350 tons/cm2.
In the line of fire - creating super shock-resistant
materials
In order to understand how it is possible
to create this ultra-strong shock absorbing
material we first need to understand the nature
of the nano material developed by ApNano. In
the early 1990's the Nano-materials Synthesis
Group in the Weizmann institute headed by Professor
Reshef Tenne, ApNano Chief Scientific Advisor,
and recent winner of the Materials
Research Society medal, together with
Dr. Menachem Genut, currently the President
and CEO of ApNano Materials, Prof. Gary Hodes
and Dr. Lev Margulis, discovered a new class
of inorganic nanostructures. The group had
found that certain inorganic compounds such
as WS2, MoS2, TiS2 and NbS2 that normally occur
as large flat platelets can be synthesized
into much smaller nano-spheres and nano-tubes
which they named inorganic fullerene-like nanostructures
or IF for short. Fullerenes are a new form
of carbon, other forms being diamond, graphite
and coal. They are molecules composed entirely
of carbon, taking the form of a hollow sphere,
ellipsoid, or tube. Spherical fullerenes are
sometimes called buckyballs, while cylindrical
fullerenes are called buckytubes or nanotubes.
Buckyballs are named after R. Buckminster Fuller,
architect of the geodesic dome that he designed
for the 1967 Montreal World Exhibition. IF
materials are Fullerene-like materials but
instead of being composed out of carbon they
can be created from various other inorganic
elements.
The new IF material produced by the Weizmann
Group was made of Tungsten Disulfide (WS2).
In contrast to organic Fullerenes, IF is easier
and much less expensive to produce, it is chemically
stable and is less reactive and consequently
less flammable. Organic Fullerenes are also
considered to be highly toxic while IF materials
have been tested extensively and deemed safe.
Tungsten Disulfide is relatively heavy and
for that reason ApNano is currently experimenting
with other materials such as Titanium Disulfide
which is at least four times lighter and is
expected to perform even better than Tungsten
Disulfide against shock waves. One of the most
interesting new IF properties discovered by
ApNano is its extremely high degree of shock
absorbing ability. Shock absorbing materials
are commonly used in impact resistant applications
such as ballistic protection personal body
armor, bullet proof vests, vehicle armor, shields,
helmets, and protective enclosures. The new
Tungsten based IF material has up to twice
the strength of the best impact resistant materials
currently used in protective armor applications
such as boron carbide and silicon carbide,
and are over 5 times stronger than steel. It
is also possible to combine IF with other substances
in order to expand their rage of capabilities.
For instance, mixing IF with highly elastic
materials can lead to new compounds which are
both flexible and shock-absorbing. These properties
position IF materials as one of the best candidates
for future protective gear and armor.
Currently ApNano can manufacture only a few
kilograms of the new material a day at their
lab in Nes Ziona. In an interview by IsraCast ,
Dr. Menachem Genut, ApNano CEO, explained that
the company is moving into semi-industrial
manufacturing within the next six months producing
between 100-200 kilograms of the material per
day, gradually moving to full-scale industrial
production by 2007, creating several tons each
day. Although it is currently still hard to
determine the exact price of the "nano-armor" when
in full industrial production, given the cost
of the original materials (Tungsten Disulfide,
Titanium Disulfide, etc.) and the relatively
low production costs, Dr. Genut stated that
a kilogram of the new material will cost considerably
less than a similar amount of the carbon-based
Fullerenes. More field testing will need to
be carried out before the nano-armor can be
declared commercial but the company is optimistic
that with some external financial backing it
will be possible to have the first product
ready in less then three years.
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