Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 12, pp. 1880−1884.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © S.N. Makhno, N.V. Konoshchuk, T.V. Chernyavskaya, A.G. Dyachenko, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86,
No. 12, pp. 1933−1937.
AND POLYMERIC MATERIALS
Electrophysical Properties of Polyaniline Doped
with Heteropoly Acids
S. N. Makhno
, N. V. Konoshchuk
, T. V. Chernyavska
, and A. G. Dyachenko
Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, Kiev, Ukraine
Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, Kiev, Ukraine
Received May 18, 2013
Abstract—Composites of polyaniline with phosphotungstic and phosphomolybdic heteropoly acids of Keggin type
were studied by impedance spectroscopy. Doping of polyaniline with these acids allows the proton conductivity
of the polymer in the composites to be increased by six orders of magnitude.
Among organic conducting polymers, polyaniline
(PAn) is one of the most stable and promising compounds.
Thanks to its electrophysical and electrochemical char-
acteristics, simplicity of preparation, and cheapness, this
seminconductor material found use in electrical engineer-
ing, electronics, optics, and other ﬁ elds [1, 2].
In contrast to crystalline compounds, in polymeric
materials there is no rigid framework, which somewhat
complicates understanding of electrochemical processes
occurring in them. Such materials are built of ﬂ exible
polymeric chains, and their main structural feature is
structural heterogeneity. Therefore, the mechanism of
ion transport in conducting polymers differs essentially
from that in solid crystalline electrolytes.
The need for developing new solid electrolytes ex-
hibiting high proton conductivity at low temperatures
promotes the development of various types of proton-
conducting materials. The development and study of
properties of solid electrolytes are stimulated by the pos-
sibility of making on their basis systems with high speciﬁ c
energy (e.g., chemical power sources) and information
converters (sensors, electrochromic indicators). In addi-
tion, studies of physical and chemical properties of solid
electrolytes with abnormally high ionic conductivity are
very important for understanding of basic principles of
ion transport kinetics in solids. Widely known proton con-
ductors with record-breaking conductivity, Keggin-type
heteropoly acids (HPAs) such as phosphotungstic (PTA)
and phosphomolybdic (PMA) acids, and also sulfonic
acid derivatives are among such materials [3, 4].
Despite ample theoretical and practical data available
in this ﬁ eld, the ion transport processes in systems with
solid proton-conducting electrolytes are still insufﬁ ciently
understood. At the same time, a study of the effect of
various factors on the proton conductivity and of the
mechanism of proton transfer is of indubitable interest.
We expected that introduction of the above Keggin-type
HPAs into a PAn matrix would allow preparation of solid
proton conductors with high transport characteristics.
In this work we studied the electrophysical properties
of PAn doped with Keggin-type HPAs (H
, М =
Мо, W) and examined the inﬂ uence of the kind of HPA
on the charge transport in the materials obtained.
Polyaniline doped with hydrochloric acid (PAn·HCl)
was synthesized by the standard procedure  and
converted into emeraldine base (PAn
) by treatment
with 1 M aqueous ammonia. To obtain PAn doped with
Keggin-type HPA (PAn·H
was redoped by keeping in a solution of the cor-
responding acid in acetonitrile for 8 h. The molar ratio
of HPA to PAn molar unit (C
N) was 1 : 6 to attain the