CONDUCTING POLYMERS MULTIFUNCTIONAL NANOCOMPOSITES

A. Nan1, R. Turcu1, D. Bica2, L. Vekas2, N. Aldea1, D. Macovei3, O.Marinica4, C.V.L. Pop1

	1National Institute R&D for Isotopic and Molecular Technologies, 71-103 Donath Str. PO Box 700,
 Cluj-Napoca, Romania
2Romanian Academy, Timisoara Branch, Magnetic Fluids Laboratory, Timisoara, Romania
3National Institute R&D of Materials Physics, PO Box MG-7 Bucuresti-Magurele, Romania
4National Centre for Engineering of Systems with Complex Fluids, Timisoara Polytechnic University, Romania

	In the past few years nanocomposite materials have become one of the most extensively studied materials all over the world as they have shown to possess several applications. Moreover, nanocomposite materials composed of oxides and conducting polymers have brought out more fields of applications such as smart windows, toners in photocopying, conductive paints, drug delivery, rechargeable batteries, electormagnetic shielding. Recently, conducting polymers with both electrical and ferromagnetic behaviours have attracted more attention.   
	The aim of the present work is the investigation of magnetic nanocomposite structures obtained by the combination between a well-known conducting polymer polypyrrole (PPy) and magnetic nanoparticles like Fe3O4.
	The magnetic nanocomposites PPy-Fe3O4 were prepared by the oxidative polymerisation of pyrrole in aqueous solution containing an oxidant, ammonium peroxodisulfate (APS) and water based magnetic nanofluid. The magnetic nanofluid was prepared by the chemical coprecipitation method to obtain magnetic nanoparticles, which were stably dispersed in water by double layer sterical stabilization with myristic acid and dodecylbenzensulfonate (DBS). The ratio of magnetic nanofluid/pyrrole was varied in the range 2-20 (v/v). The reaction proceeded at room temperature under magnetic stirring for different time intervals between 6 to 20 h. 
	The properties of the composite were investigated by TEM, SEM, FTIR spectroscopy, d.c. conductivity, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and magnetisation measurements.  
	The nanocomposite PPy-Fe3O4 have a core-shell structure where Fe3O4 is the magnetic core and PPy is conducting shell. The changes of nanocomposites properties by the synthesis parameters are presented.