Slajd 1

1
O n t h e T r a c k o f M o d e r n
P h y s i c s
A mistery from the chimney
We all know that graphite and diamond are two
carbon forms one is grey, fragile, made of
slipping hexagons, another brilliant, cubic and
hard. But what about a common sooth from a
chimney? It is black and seems fatty. Only in
1985, R.F. Cure, H. W. Kroto, and R. E. Smalley
discovered in deposits from carbon electric arc a
new form, an empty cage, made of 60 carbon atoms,
called fullerene. Now it is a whole family.
Fullerenes were under study for potential
medicinal use binding specific antibiotics to
the structure to target resistant bacteria and
even target certain cancer cells such as
melanoma. Attaching potassium, lithium or
rubidium atoms they become superconductors.
C20
C60
C80
C180
The comparatively stable C60 was the first to be
discovered, but several other members of the
family have now been made. Big fullerenes are no
more spherical.
C540
Carbon nanotubes, long, thin (a diameter of close
to 1nm) cylinders of carbon, were discovered in
1991 by S. Iijima (NEC, Tsukuba, Japan)
Nanotubes, depending on their structure, can be
metals or semiconductors.  They are also
extremely strong materials and have good thermal
conductivity. They can be used as nano-wires or
as active components in electronic devices such
as the field-effect transistor. Nanotubes can be
opened and filled with biological molecules. They
can be also used to dissipate heat from tiny
computer chips.
Matrioshka?
Properties of nanotubes depend on their
structure. A semiconductor diode can be formed by
joining two nanoscale carbon tubes with different
electronic properties.
The thermal protection system of space-shuttles
consists of various materials. Reinforced Carbon
Carbon (RCC) components protect the shuttles
nose section, wing leading edges and chin panel
from extreme heat.
When you go to a sports shop you are inundated
with new carbon-based equipment golf clubs,
tennis rackets, bicycles, ultralight airframes
and yachts.
So-called amorphous carbon, usually with some
admixture of hydrogen, makes covers which are
extremely hard. If You do not believe, try to
clean Your frying pans.
Playing Chinese pans, Dahlem Dorf Museum, Berlin,
photo Maria Karwasz
4/4