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A hybrid approach has been adopted by using a combination of colloidal graphite (CG) as a conducting filler, 5-lithium sulfoisophthalic (LiSIPA) acid as a dopant, and polyaniline (PANI) as a matrix to prepare LiSIPA doped PANI-CG composites. The thermal stability (∼300°C) and electrical conductivity (67.4 S/cm at 17.4% CG content) have been improved significantly as compared to PANI doped with conventional inorganic dopants like HCl or H2SO4 (130-150°C). The maximum shielding effectiveness value was found to be −39.7 dB. X-ray diffraction and infrared spectroscopy showed a systematic shifting of the characteristic peaks and bands with increase in the amount of CG, which indicates significant interaction exists between CG and PANI. The UV-Vis spectra showed the characteristic bands of PANI, with a shift to shorter wavelength with increase in the CG content. The interaction mechanism between doped PANI and CG in the resultant composites has been proposed. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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- γ-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 γ-Fe2O3 show super-paramagnetic behavior at room temperature which was also observed in PEDOT- γ-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°C. The characterization of the PEDOT- γ-Fe2O3 composite was carried out using XRD and FTIR spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The paper reports the designing and development of conducting polyaniline composites which show a shielding effectiveness of 4-58 dB against electromagnetic interference at 101 GHz range, depending upon the loading of the conducting polyaniline in polystyrene and polymethylmethaacrylate matrix. The composites can be used for the dissipation of static charge. A static decay time of the order of 0.11-0.02 s for the conducting polyaniline composites is observed when the charge is reduced from 5000 to 500 V. [ABSTRACT FROM AUTHOR]

Conducting polymer nanocomposites of polyphenyl amine with barium ferrite nanoparticles (50–70 nm) have been synthesized via emulsion polymerization. The complex permittivity, permeability, and microwave absorption properties of the composite were studied in the 12.4–18 GHz (Ku band) frequency range. The composite has shown high shielding effectiveness due to absorption (SEA) of 28.9 dB (∼99.9%), which strongly depends on dielectric loss, magnetic permeability, and volume fraction of barium ferrite nanoparticles. The high value of SEA suggests that these composites can be used as a promising radar absorbing materials. [ABSTRACT FROM AUTHOR]

The present paper reports the synthesis and characterization of poly (o-toluidine) (POT) embedded with barium ferrite and reduced graphene oxide. Barium ferrite nanoparticles (BF) were prepared by citrate precursor technique. Synthesis of reduced graphene oxide (RGO) from graphite powder was carried out by improved Hummer's method. Composite of poly (o-toluidine) with barium ferrite and reduced graphene oxide (POT/BF/RGO) was synthesized by in-situ polymerization method. The formulation shows total shielding effectiveness of 12.07 dB in the X-band (8.4-12.4 GHz) frequency range. Permeability and dielectric parameters have been calculated from the measured scattering parameters (S11, S22, S12, S21) using the Nicolson-Ross-Weir algorithm. The synthesized formulations were characterized using x-ray diffraction (XRD), scanning electron microscope (SEM), Transmission electron microscopy TEM, Ultraviolet-visible spectroscopy (UV-Vis) and vibrating sample magnetometer (VSM). [ABSTRACT FROM AUTHOR]