1070-4272/03/7609-1497$25.00C2003 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 76, No. 9, 2003, pp. 1497!1501. Translated from Zhurnal Prikladnoi Khimii, Vol. 76, No. 9,
2003, pp. 1536!1540.
Original Russian Text Copyright + 2003 by Alekhin, Kirilenko, Lapshin, Romanov, Sigarev.
AND POLYMERIC MATERIALS
Nanostructured Carbon Coatings on Polyethylene Films
A. P. Alekhin, A. G. Kirilenko, R. V. Lapshin, R. I. Romanov, and A. A. Sigarev
Lukin Research Institute of Physical Problems, Federal State Unitary Enterprise, Moscow, Russia
Received May 26, 2003
Abstract-The properties of medical low-density polyethylene films with carbon coatings improving the
biological compatibility of the polymer were studied by electron and scanning atomic-force microscopy,
as well as by IR, Raman, visible, and UV spectroscopy.
A promising line in development of hemocom-
patible materials is modification of the polymer sur-
face by deposition of coatings having the desired bio-
chemical properties . Understanding of the forma-
tion mechanism of hemocompatible surfaces requires
studying the properties of the modifying coating.
Among the materials suitable for modification of
medical polymers, in particular, low-density poly-
ethylene (LDPE), is carbon  with its unique proper-
ties, above all, the occurrence in various chemical
sp (carbyne). Carbon is expected to be well compat-
ible biologically with blood plasma proteins and liv-
ing cells of the human body, because these cells con-
sist, primarily, of organic, i.e., carbon-containing
compounds. Lastly, it is possible to build on the sur-
face of a polymer support the required cluster forma-
tions from carbon (nanostructured carbon), matching
in the thermodynamic and geometric parameters a cer-
tain type of molecules of blood plasma proteins. This
makes possible formation of a high-quality polymer3
blood interface when using carbon as the modifying
In this work, we studied LDPE-supported nano-
structured carbon by physical methods.
As the model material for the support we used a
50-mm-thick film of LDPE [GOST (State Standard)
10354382]. Rectangular 25020-mm pieces of the
LDPE film were cut out in a such way that their
longer sides made the same angle with the axis of film
extension during its preparation.
Carbon coatings were deposited onto the polymer
films in a working chamber of a UVNIPA-1 vacuum
setup (manufactured by the Kvarts Kaliningrad Mach-
ine-Building Plant) by pulse plasma-arc spraying of
a graphite target at the residual gas pressure of ca.
7.5 0 10
torr. The LDPE sample was fixed in a
holder at a distance of 35 cm from the carbon target
surface; the working surface of the polymer was per-
pendicular to the direction of propagation of the car-
bon ion flow.
The ignition electrodes in the UVNIPA-1 setup
were used for initiating a ~0.01-s pulse electric-arc
discharge on the surface of a cold in the bulk graphite
cathode. The discharge produced carbon plasma
whose ions were then accelerated in an electric field
with a potential difference of 450 V and condensed on
the working surface of the support. The sample sur-
face was modified at various frequencies f of the
pulses generated by the carbon plasma generator (0.1,
0.3, and 1 Hz).
The pulsed condensation of the carbon coating
(with the pause being more than 10 times longer than
the plasma discharge period) improves the heat re-
moval from the carbon coating condensation zone.
This makes less probable melting of the structural ele-
ments of the polymer matrix and favors stabilization
of the surface modification process. The setup used
by us provided the carbon film deposition rate of
~0.15 nm per pulse. We estimated the rate constant of
the coating thickness growth by X-ray photoelectron
spectroscopy using the procedure from . For com-
paring the modified and initial LDPE film surfaces,
a segment of the sample was shielded from the ion
beam. The thickness of the deposited carbon films
was 1.5315 nm on the average, which corresponds to
N =103100 pulses of the coating deposition.
The LDPE film surface morphology was examined
by scanning probe atomic-force microscopy (AFM)