Preparation and electrical conductivity of SiO
2
/polypyrrole
nanocomposite
Qunwei Tang Æ Xiaoming Sun Æ Qinghua Li Æ
Jianming Lin Æ Jihuai Wu
Received: 23 September 2008 / Accepted: 25 November 2008 / Published online: 11 December 2008
Ó Springer Science+Business Media, LLC 2008
Abstract In the present study we have chemically poly-
merized silica/polypyrrole (SiO
2
/PPy) nanocomposite in
the presence of sodium dodecyl benzene sulfate (SDBS) as
dopant and iron chloride (FeCl
3
) as oxidant. The SiO
2
/PPy
nanocomposite presents an electrical conductivity of
32.41 S cm
-1
and percolation threshold of 20 wt%. The
resulting SiO
2
/PPy nanocomposites have been extensively
characterized in terms of their molecular structure, particle
size, morphology, stability, and electroactivity. These
SiO
2
/PPy particles have a rather polydisperse morphology.
The effects of synthesis parameters such as oxidant, PPy,
SDBS, reaction temperature and time, on the electrical
conductivity of the nanocomposite have been detailedly
optimized. And the conducting nanocomposite presented a
good environmental stability.
Introduction
One of the current interests in research on nanostructured
materials is the preparation of nanocomposite conducting
colloidal particles consisting of inorganic component and
conducting polymers. The optical and electrical properties
of these materials differ from their individual nanoparticles
or macroscopic equivalents. Therefore they can be effec-
tively applied in the fields of sensors, optics, and electronics.
Techniques for the preparation of nanocomposites contain-
ing conducting polymers have been reviewed [1].
Conducting polymers such as polypyrrole (PPy) have
attracted considerable attention in the past two decades for
their potential applications in electromagnetic radiation
shielding, microwave absorbent and battery, et al. [2–5].
Of all known conducting polymers, PPy has been an object
of intense investigation because of its good conductivity,
stability in air, interesting electrochemical behavior, cor-
rosion protection, and ease of preparation [6]. It can be
prepared by two main routes, the chemical [7, 8] and the
electrochemical [9] oxidation of pyrrole in organic solvents
and in aqueous media. As known, the conductivity of PPy
can be attributed to the hop electrons along and across the
polymer chains with the conjugating bonds [10]. Owing to
the preparation method and doping, the conductivity of PPy
can be improved heavily to an attractive level [11–13].
Conducting polymer-based nanocomposites decorated
with oxides or metallic nanoparticles provide exciting sys-
tems to investigate with the possibility of designing device
functionality. There have been numerous publications
describing the preparation of inorganic–organic hybrid
materials which contain PPy as the organic component. For
example, Partch et al. have described the preparation of
several PPy-coated inorganic oxide composites by utilizing
the inorganic oxide as a colloidal oxidant [14]. Mehrotra
et al. have synthesized PPy-silica ‘‘hybrid glasses’’ by the in
situ chemical polymerization of pyrrole in a host glass matrix
containing copper ions [15]. Yoneyama and co-workers have
incorporated a wide range of particulate inorganic oxides
such as titanium oxide, tungsten oxide, and manganese oxide
into electrochemically synthesized thin films of PPy [16]. In
addition, Yamamoto’s group have synthesized organic–
organic hybrid particles which are apparently colloidally
stable by polymerizing pyrrole onto the surface of
poly(styrene-co-butadiene) latexes [17]. There are other
studies on synthesis, characterization and application of
Q. Tang Á X. Sun Á Q. Li Á J. Lin Á J. Wu (&)
The Key Laboratory for Functional Materials of Fujian Higher
Education Institute of Material Physical Chemistry, Huaqiao
University, Quanzhou 362021, China
e-mail: jhwu@hqu.edu.cn
123
J Mater Sci (2009) 44:849–854
DOI 10.1007/s10853-008-3137-5