Polipirrol Electrodepositado

ELECTRODEPOSITED CONDUCTING POLYMER – FERROMAGNETIC COMPSITES J.M. Ko∗, D.-Y. Park, N.V. Myung and K. Nobe Department of Chemical Engineering University of California, Los Angeles, CA 90095-1592
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INTRODUCTION
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Conjugated polymers have attracted considerable interest since the discovery of conducting polyacetylene in 1977 [1]. Since then, an enormous amount of work has goneinto developing electronic and transport properties of conjugated polymers for various applications. Among the various conducting polymers, polypyrrole (PPy) has a relatively high conductivity andremarkable stability [2]. It has been reported that PPy doped with dodecylsulfate (DS) anion, (PPy-DS), shows good mechanical properties and electrochemical stability [2-4]. In particular, when the PPy-DSis electrochemically reduced, DS anions are not removed from the bulk PPy film in electrolyte solutions due to their size. Instead of the elimination of DS anions, small cations such as Li+, Na+, K+are inserted into the bulk PPy film for charge neutralization. In the present study, PPy/ferromagnetic binary and multilayers were electrodeposited, and their magnetic and electrical propertiesinvestigated. EXPERIMENTAL PPy films doped with dodecylsulfate, (PPy-DS), were prepared by electrochemical oxidation of pyrrole in aqueous solutions containing 0.36 M pyrrole monomer and 0.036 M NaDS as asupporting electrolyte [2]. PPy-DS was first electrochemically polymerized at 1 mA cm-2. Then, magnetic materials (Co, Ni, NiFe, CoMnP) were electrodeposited at 0.5 mA cm-2. The magnetic properties andthe microstructure of films were characterized using a vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM), respectively. RESULTS AND DISCUSSION Figure 1 shows the surfacemorphologies of electrodeposited PPy-DS/ferromagnetic bilayer. Figure 1a shows a typical surface of electrodeposited PPy film with rough spherical grains. As the magnetic metal is electrodeposited on PPy,...