Synthetic Metals 158 (2008) 1009–1014 Contents lists available at ScienceDirect Synthetic Metals journal homepage: www.elsevier.com/locate/synmet Synthesis and characterization of poly(3-octylthiophene)/-Fe 2 O 3 nanocomposite—A promising combination of superparamagnetic–thermoelectric–conducting properties Csaba Janáky, Csaba Visy ∗ Institute of Physical Chemistry, University of Szeged, Rerrich t. 1, H-6720 Szeged, Hungary article info Article history: Received 8 November 2007 Accepted 3 July 2008 Available online 7 September 2008 Keywords: Poly(3-octylthiophene) Maghemite Nanocomposite Superparamagnetic Thermoelectric abstract We report on the synthesis of poly(3-octylthiophene)/-Fe 2 O 3 nanocomposite by realizing the trans- fer of maghemite nanoparticles from aqueous solution to organic media. Monomer was polymerized in non-aqueous chloroform in the presence of the dispersed iron-oxide particles. The iron-oxide content of the composite was determined by atom absorption spectroscopy (ICP-AAS) and energy dispersive X-ray microanalysis technique (EDX). The molecular structure was characterized by UV–vis spectroscopy and photoacoustic Fourier transform infrared spectroscopy (PAS-FTIR). X-ray diffraction (XRD) was used to characterize the supramolecular structure. Morphology change could be followed by scanning electron microscopy (SEM) which shows that the presence of maghemite particles during the synthesis results in a more compact structure consisting of spherical particles. The effective chain-length did not alter in com- parison with the net polymer, moreover the structural change can be well correlated with the conductivity and capacity increase, determined from AC impedance spectroscopy measurements. The successful syn- thesis of the new composite possessing conducting, superparamagnetic and thermoelectric properties, can lead to possible applications. © 2008 Elsevier B.V. All rights reserved. 1. Introduction In the past decade, investigation of composite materials became one of the most extensively studied research area, assumingly due to their novel features and wide-scale utilization possibilities. The composites of conjugated polymers and inorganic compounds are in the focus of interest because they open opportunity for the com- bination of special optical, magnetic, catalytic, photocatalytic, etc. properties with the electric conductivity. These special attributes may lead to several applications, such as in microwave absorb- ing materials, electrocatalytic systems, electrical-magnetic shields, optical devices, batteries, etc. During the recent years an increasing attention is paid for nanomaterials, because new interesting prop- erties seem to develop with the size diminution of particles towards nano dimensions. Basically two types of nanomaterials, based on conducting polymers, are extensively studied. In one of the cases the polymer itself is nanostructured [1,2], while in other cases the polymer contains nanosized inorganic particles. This area of conju- gated polymer based new materials is more and more intensively studied [3]. ∗ Corresponding author. Tel.: +36 62544667; fax: +36 62544652. E-mail address: visy@chem.u-szeged.hu (C. Visy). According to literature data, conducting polymer composites with metals/oxides/sulfides/carbon-nanotubes and zeolites have been successfully realized [4–12]. The incorporation of different iron-oxide into conjugated systems is of special interest since such nanocomposites may involve the combination of magnetic and electric properties. Such materials like -Fe 2 O 3 (maghemite) and Fe 3 O 4 (magnetite) have superparamagnetic and/or ferromagnetic behavior depending on the particle size. Different composites of these iron-oxides in polypyrrole, polyaniline and PEDOT have been already reported [13–18]. Composites of conducting polymers are generally characterized with wide scale of methods used in material science. Some of the investigations focused on the influence of the composite for- mation on the conductivity change of the polymer matrix, since the presence of the non-conducting component may modify this fundamental property. In this sense results are contradictory in the different papers, as both conductivity increase and decrease have been observed [13,14,19]. For this reason, we consider very important to combine conductivity and structural measurements together, to be able to interpret the eventual conductivity change in terms of structural alterations. Although many reports are available on synthesis in aqueous solutions for PPy/PANI/PEDOT based magnetic nanocomposites, only a single attempt can be found for those of other polythiophenes 0379-6779/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.synthmet.2008.07.014