1070-4272/03/7603-0378$25.00C2003 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 76, No. 3, 2003, pp. 378!382. Translated from Zhurnal Prikladnoi Khimii, Vol. 76, No. 3,
2003, pp. 393!397.
Original Russian Text Copyright + 2003 by Iordanova, Korsakov, Tsvetkova, Mitev.
AND ION-EXCHANGE PROCESSES
Effect of the Surface Nonuniformity of Dispersed Diabase
on Properties of Composites
E. N. Iordanova, V. G. Korsakov, M. N. Tsvetkova, and D. T. Mitev
St. Petersburg State Technological Institute, St. Petersburg, Russia
Zlatarov University, Burgas, Bulgaria
Received January 23, 2001; in final form, November 2002
Abstract-Adsorption of acid3base (Hammett) indicators and Fe(III) hydroxo complexes on the surface
of dispersed diabase containing 45352% silica, which is a promising polymer filler, was studied. Changes
in the energy-related characteristics of the surface in the course of grinding and chemical modification of
diabase with carbon from a mixture of CCl
Controlling the energy-related characteristics of
the surface of dispersed solids is a promising direction
in developing structural and functional polymeric
composites with prescribed properties. By varying the
dispersity and the composition of functional groups,
one can affect the donor3acceptor properties of com-
ponents, interactions at the interface between the
dispersed component and the polymer, and properties
of composites. Wide use of inexpensive natural ma-
terials instead of synthetic materials as fillers of poly-
meric composites is hindered by their inhomogeneity.
The reproducibility of properties can be improved,
and the interaction energy at the interface between the
dispersed filler and the polymer and the structure of
the interfacial layer can be optimized by polymer
grafting , local chemical modification of the sur-
face, or synthesis of nanometer coatings by chemical
assembly technique . This is only possible for
dispersed materials whose particles have a strong 3D
(mainly covalent) framework and bear reactive func-
tional groups on the surface.
In this work we examined the possibility of chemi-
cally modifying with carbon the surface of dispersed
diabase produced as waste in manufacture of building
materials and also studied the functional composition
and energy nonuniformity of the initial and modified
Diabase samples [magmatic rock strongly modified
by secondary processes, with silica content of 45352%
; Dzhebel deposit, Bulgaria; mineralogical (phase)
composition: plagioclase, pyroxene, olivine, horn-
blende] were ground in a ball mill and fractionated
(particle diameter in different fractions 203125 mm).
The diabase surface was modified with carbon on
a laboratory setup (Fig. 1) in fixed bed in a quartz
reactor from a mixture of CCl
at 500oC for
1 h. Methane was purified with active copper and
sorbents to remove oxygen and water vapor in units 1
and 2 and was saturated with tetrachloromethane
vapor in a bubbler 3 and fed into reactor 4 having
the form of a quartz tube 260 mm long and 46 mm in
diameter with external Nichrome coil for heating.
A quartz grid with 0.531-mm openings was welded
within the reactor at a height of 60 mm. The grid was
covered with glass fiber fabric on which a 50-g por-
tion of diabase was placed. The temperature of the
diabase bed was measured with a thermocouple and
controlled and recorded with EPP-09 electronic poten-
tiometers 5 and 6. The reaction proceeds in accor-
dance with the equation
6 2C + 4HCl.
Hydrogen chloride formed in the reaction was ab-
sorbed with a 0.1 N NaOH solution in vessel 7.
Fig. 1. Schematic of the laboratory setup for modification
of dispersed diabase with carbon in fixed bed (for explana-
tions, see text).