Eur. Phys. J. E 19, 149–154 (2006) DOI: 10.1140/epje/e2006-00027-2 T HE EUROPEAN P HYSICAL JOURNAL E Formation of palladium nanoparticles in poly (o -methoxyaniline) macromolecule fibers: An in-situ chemical synthesis method K. Mallick 1 , M.J. Witcomb 2 , and M.S Scurrell 1, a 1 Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa 2 Electron Microscope Unit, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa Received 1st March 2003 / Received in final form 15 November 2004 Published online 7 March 2006 – c  EDP Sciences, Societ`a Italiana di Fisica, Springer-Verlag 2006 Abstract. We report here a novel in-situ synthetic method for the preparation of poly (o-methoxyaniline) and palladium nanoparticle composite material. Ortho -Methoxyaniline and palladium acetate were used as the precursors; during the reaction o-methoxyaniline was oxidized and forms poly (o-methoxyaniline) and palladium acetate is reduced forming palladium nanoparticles. IR and Raman spectra provide information on the structure of the polymer. The TEM and SEM analysis are used to determine the size of the nanoparticles and the morphology of the polymer respectively. PACS. 81.07.Pr Organic-inorganic hybrid nanostructures – 81.16.Rf Nanoscale pattern formation – 82.35.Cd Conducting polymers 1 Introduction Composite architectures of polymer and metal nanoparti- cles synergistically provide both useful functionality and mechanical integrity. Metal nanoparticles combined with the conducting polymer form a unique composite with in- teresting physical properties and potential applications. Such composites show various properties directly relevant and of benefit to dielectrics, energy storage and catalytic activity [1]. Many investigations regarding the development of the incorporation technique of the metal nanoparticles into the polymer matrix have been published. Three different approaches have been utilized to make such composite ma- terial, such as: 1. in-situ preparation of the nanoparticles in the matrix. This is effected either by the reduction of metal salts dissolved in the polymer matrix [2–4] or by the evaporation of metals on a heated polymer surface [5]; 2. polymerizing the matrix around the nanoparticles [6]; 3. in-situ formation [7] of the polymer from its monomer and the metal nanoparticles from its ionic precursor. The latter method is likely to provide a high degree of synthetic control over both the size of the nanoparticles, the mor- phology of the polymer matrix, and this in turn may be ex- pected to exert a strong influence on the metal-polymer in- teraction. Interesting chemical properties may well result. The incorporation of metal nanoparticles into conduct- ing polymers provides enhanced performance for both the “host” and the “guest”, and this can lead to different phys- ical properties and important potential applications [1]. a e-mail: scurrell@aurum.wits.ac.za In order to exploit the full potential of the technologi- cal application of the composite material, it is crucial to characterize the nature of the association between the dif- ferent components. While the incorporation of gold, cop- per and palladium nanoparticles into conducting polymers has been reported by using chemical or electrochemi- cal techniques, the synthesis of conducting polymer-metal nanoparticle composite materials having a nanofiber-like morphology has not yet been undertaken. The preparation of gold nanoparticle-polyaniline com- posite material has been reported using preformed polyaniline by exploiting the multi-oxidative states of the polymer [8,9]. Use of hydrogen peroxide, which acts both as an oxidizing and a reducing agent, has been reported to produce a gold-polyaniline composite [10] having gold particle sizes of 26 nm (as evidenced by XRD analysis). Also documented has been the preparation, using HBF 4 , of a gold-polyaniline composite material, which had gold particles in the 0.8–1.0 μm size range [11]. Recently, we reported [12] on a gold-polyaniline composite material formed in a toluene solution by using a phase transfer cat- alyst. Polyaniline nanoballs of a few microns in size were decorated with gold nanoparticles (10–50 nm). The meth- ods reported to date tend to produce relatively large gold particles. There is, therefore, a need to develop a synthetic approach to enable readily nanosized metal particles to be obtained. Reports have been published on the synthesis of a Cu-polyaniline composite material using a sonochemical synthetic route in which copper (II) acetate and aniline were irradiate with a high-intensity ultrasonic horn under