Poly(3,4-ethylenedioxythiophene) γ-Fe2O3 polymer composite-super paramagnetic behavior and variable range hopping 1D conduction mechanism-synthesis and characterization

The present paper reports the preparation of poly (3,4-ethylenedioxythiophene) (PEDOT) ferrimagnetic conducting polymer composite by incorporation of ferrite particles in the polymer matrix by emulsion polymerization. Synthesis of PEDOT-gamma-Fe2O3 composite was carried out by chemical oxidative polymerization of EDOT with ferrite particles in the presence of dodecylbenzenesulfonic acid (DBSA) that works as dopant as well as surfactant in aqueous medium. The resulting conducting composite possesses saturation magnetization (Ms) value of 20.56 emu/g with a conductivity of 0.4 Scm(-1), which was determined by VSM and four probe technique, respectively. B-H curve reveals that ferrimagnetic particles of gamma-Fe2O3 show super-paramagnetic behavior at room temperature which was also observed in PEDOT-gamma-Fe2O3 Composite. The resulting conducting ferrimagnetic composite shows microwave absorption loss of 18.7-22.8 dB in the frequency range of 12.4-18 GHz. Thermogravimetric analysis of the composite revealed that the composite is thermally stable up to 230 degrees C. The characterization of the PEDOT-gamma-Fe2O3 composite was carried out using XRD and FTIR spectroscopy. Copyright (c) 2007 John Wiley & Sons, Ltd.