Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 11, pp. 1681−1685.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © Zh.I. Bespalova, A.V. Khramenkova, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 11, pp. 1771−1775.
TECHNOLOGY OF ELECTROCHEMICAL
AND OTHER INDUSTRIES
Preparation of Oxide and Metal-Complex
Polymer-Immobilized Composite Coatings on the Steel Surface
Zh. I. Bespalova and A. V. Khramenkova
South-Russian State Technical University (Novocherkassk Polytechnic Institute), Novocherkassk, Russia
Received August 24, 2012
Abstract—The possibility of preparing oxide and metal-complex polymer-immobilized composite coatings on
the steel surface with the use of alternating asymmetric current was studied.
The electrochemical synthesis of complicated oxide
materials by the deposition from mixed aqueous solutions
of salts of coprecipitated metals is of essential interest
[1–4]. One of promising directions in this ﬁ eld of research
is the development of composite coatings, which present
oxide and metal-complex polymer-immobilized systems.
They have a wide spectrum of practical application,
from catalysts up to nanotechnology in the informational
technique. However, up to now only chemical methods
were applied to immobilize oxides and metal complexes
in various polymer arrays .
Data on the preparation of polymer-immobilized coat-
ings based on metal oxides precipitated from aqueous so-
lutions of their salts with the use of alternating asymmetric
current are absent from the literature. At the same time
this research line is rather promising, as the application
of alternating asymmetric current for the formation of
such coatings uncloses great possibilities for controlling
structure and properties of the forming coatings.
The aim of the present work was to obtain composite
coatings based on molybdenum, cobalt, nickel, and iron
oxides deposited on a steel surface from aqueous solutions
of their salts upon polarization by alternating asymmetric
current and immobilized in a polymeric matrix.
The redox-conductivity, sensory, and catalytic prop-
erties of polymer-immobilized compositions are among
their major functional properties deﬁ ning urgency of
research in this direction.
Formation of polymer-immobilized composite coat-
ings was carried out on the surface of St.3 steel prepared
preliminarily by the standard procedure . We applied
polarization by alternating asymmetric current of the
power-line frequency representing two half-sinusoids of
different amplitudes. The average current density was
0.1–0.9 А dm
, temperature 65–70°С, рН 4, and the
depositing time 60 min.
A temperature-controlled glass electrolyzer of 200 ml
volume served as an electrochemical cell, in which
a working electrode, a counter electrode, and a magnetic
stirrer were placed. Macroelectrodes of size 30 × 20 ×
0.2 mm (from the both sides) made from the St.3 steel
were used as working electrodes, and a counter electrode
was made from stainless steel or cobalt. Oxides were
precipitated from aqueous solutions of electrolytes con-
taining (M): iron(II) sulfate (FeSО
О) 0.02, cobalt
О) 0.40, ammonium paramolybdate
O] 0.05, nickel sulfate (NiSО
0.07, boric acid (Н
) 0.20, and citric acid (С
0.02; gelatin was taken at the rate of 2.0 g l
acid in the composition of electrolyte played the role
of a stabilizing and complex-forming component. It al-
lowed us to keep iron in the divalent state and provided
a high stability of the electrolyte. Gelatin was added to
the electrolyte to obtain immobilized systems, in which
metal oxides are ﬁ xed or metal complexes are formed.
The coatings were 13.0–15.0 μm thick, as determined