seems, everything is known about carbon. However,
there also exists nanofibrous carbon. This particular
carbon has recently been often used as a catalyst
and electrode material, and also as a splendid adsorbent.
Therefore, it can also be used for detrimental impurities
refinement, and it can be added to diverse polymers
to improve their characteristics.
carbon is interesting by itself: it consists of carbon
fibres of 3 to 500 nm in diameter. These fibres can
form " cylinders" (which make almost finished
polymeric nanotubes), or a system of cones stowed
one into the other at a certain angle to the fibre
axis, or simply "wrapping package" – this
is driven by the type of applied catalyst and conditions
for getting this promising material.
It is interesting to note that the process of obtaining
the material is rather simple, therefore the process
allows to reclaim various hydrocarbon gases, which
in this case become an ideal source of raw materials
for production of two very valuable substances - hydrogen
and nanofibrous carbon.
The reaction needs a plant which would ensure ideal
stirring of the mixture of methane with inert gases
(argon, helium or nitrogen) in a microreactor, and
nickel catalyst produced under a special method (sol-gel),
as a result of which the size of nickel nanoparticles
varies from 12 to 60 nm in diameter.
The researchers noticed an interesting phenomenon
in the course of the experiment: nanoparticls of the
catalyst self-organized. It was ascertained that self-organization
is provoked by temperature. For example, the phenomenon
was not observed at 500º?, but already at 550º?
self-organization took place. When the original size
of nanoparticles makes 12 nm, they spontaneously enlarge,
but the particles of 60 nm in diameter decrease in
size. This interesting puzzle is worth noting and
the researchers are going to solve it in the near-term
The thickness of nanofibers can be altered by changing
the temperature and composition of the gas mixture.
For instance, using only pure methane at the temperature
of 500º?, the fiber can be as thick as 50-60
nm in diameter, but if the mixture consists of methane
and argon in equal shares and the mixture is processed
at 600º?, the fibres get thinner - 30 - 40 nm
in diameter. The thinnest fibres will be obtained
if the methane content is decreased down to 10% -
the fibres diameter will make 20 nm.
It turns out that the thickness of bibres can be altered
and the form of their packing can be chosen. That
opens wide perspectives for creative work, moreover,
this is to the benefit of the environment. This is
a kind of wasteless industry - unneeded carbohydrates
can be used for manufacturing important products.
However, it is still to be determined how and why
different catalysts impact the type of the carbonic