CARBON PRECURSORS FOR SYNTHESIZING
OXYGEN-FREE REFRACTORY NEW FORMATIONS
IN CARBON-GRAPHITE MATERIALS
G. D. Semchenko
, M. A. Panasenko
, O. I. Zelenskii
, and V. Yu. Baklan
Translated from Novye Ogneupory, No. 6, pp. 35 – 38, June 2010.
Original article submitted November 18, 2009.
Types of carbon nanostructures that are used for synthesizing nanofibers within carbon-graphite materials in
order to improve their physicomechanical properties are considered.
Keywords: carbon precursor, synthesis, SiC, Si
Synthesis of nanosize and micron-size new formations
from gels occurs at low temperature . Thermodynamically
it has been established  that in the system Si–O
thesis possibly starts from 550°C due to presence within it of
very small amounts (10
) of silicon monoxide. A carbon
precursor may be any carbon-containing substance or com-
pound. If a carbon precursor, serving as a substrate for sili-
con monoxide vapor, is atomic carbon, fullerines and
nanotubes, then nanosize compounds are synthesized (SiC,
C, etc.), if the carbon source is pitch and graphite,
then crystals of micron size of these compounds are synthe
sized. In the technology for structural ceramics and car
bon-containing refractories using elements of the sol-gel pro
cess it is quite easy to create conditions for self-organization
of matrix structures and creation of nano-reactors for synthe
sizing nanosize particles and filamentary crystals within
Carbon is known in the form of diamond, graphite, coal,
soot, coke, carbon fibers, pitch, carbon particles, fullerines,
nanotubes and other varieties. Not all of them may be used in
ceramic technology for energy saving technology of synthe
sizing refractory nanosize new formations. In order to accel
erate synthesis of naonofibers within the pores of car
bon-graphite materials we have proposed use as a carbon
precursor atomic carbon, forming as result of thermal de
struction of gels, and nanotubes obtained by different meth
ods from various sources of carbon nanostructures .
Abroad there is extensive work on preparing nanotubes
from carbon in an arc discharge , and the CVD method
(precipitation from a gas phase) , nanotubes and fullerines
from brown coal , double-walled  and sin-
gle-walled nanotubes . It has been established that the
properties of the organic part of carbon and associated ele-
ments of its mineral part plays an important role in forming
nanotubes . It has been established that from pitch and
coke it is possible to obtain single-walled nanotubes, but in
smaller quantities than from graphite.
With use of a sol-gel binder in the technology of car
bon-graphite objects from a pitch and binder mix new forma
tions are also synthesized in the shape of fibers at the walls
of pores (Fig. 1), but the porosity of carbon-graphite speci
mens based on sol-gel binders is hardly reduced (Table 1),
and this is connected with insufficient compaction of a mix
based on anthracite and graphite during compaction.
In order to synthesize oxygen-free new formations in
carbon-graphite materials we have used nanotubes from
Refractories and Industrial Ceramics Vol. 51, No. 3, 2010
1083-4877/10/5103-0193 © 2010 Springer Science+Business Media, Inc.
NTu KhPI, Khar’kov, Ukraine.
UKhIN, Khar’kov, Ukraine.
I. I. Mechnkov ONU, Odessa, Ukraine.
Fig. 1. Synthesis of new formations in the form of fibers on pore
walls (shown by arrows).