Dielectric properties of nano ZnO-polyaniline composite in the microwave frequency range

Films of polyaniline (PANI) and PANI-nano ZnO composites have been synthesized by solution casting technique. Fourier transform infrared spectroscopic studies of PANI and PANI-nano ZnO composite films indicated the presence of interaction between nanoZnO particles and molecular chains of PANI. Dielectric properties of the PANI and composite films have been investigated in the frequency range of 8.0-12.0 GHz. The real part of permittivity (epsilon') and loss factor (tan delta) were found to decrease in PANI-nano ZnO composite films. The decreasing behavior of epsilon' and tan delta may be attributed to the interaction between nano ZnO particles and PANI molecular chains. The interaction between PANI chains and surface of ZnO nano particles restricts the motion of the dipoles and leads to the decrease of epsilon' and tan delta of the composite films. (C) 2008 Elsevier B.V. All rights reserved.