Preparation and microwave adsorption properties of core-shell structured barium titanate/polyaniline composite

Nano-BaTiO3 particles were prepared by the sol-gel method. The core-shell structured BaTiO3/polyaniline (PANI) composites were synthesized by in-situ polymerization with as-prepared BaTiO3 nano-particles. The structural, morphology and microwave adsorption properties of the obtained composites were investigated in detail by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and vector network analyzer. The average particle size of the BaTiO3 nanoparticles was measured to be 60 nm and the thickness of shell was 40 nm. The complex permittivity, permeability and reflection loss of the composites were measured at different microwave frequencies in 0-6000 MHz. The effect of the mass ratio of BaTiO3/PANI on the microwave loss properties of the composites was investigated. For the sample obtained by the mass ratio of BaTiO3 to PANI of 4:1, the value of reflection loss peaks is up to -14.5 dB. The width of the -5 and -10 dB is up to 1200 and 750 MHz, respectively. This reveals that the BaTiO3 nanoparticles in the polyaniline matrix affect the microwave absorption properties of the nanocomposites. (C) 2012 Elsevier B.V. All rights reserved.