Study of Mechanical and Electrical properties of PS/PANI/Hexaferrites Nanocomposites

Abstract

Nanocomposites form an important class of nanomaterials as they encompass variety of different properties owing to their non-similar components. Nanocomposites are a very favorable candidate for a commercial EMI shielding material. For this purpose, a lightweight matrix of Polystyrene (PS) and conductive and magnetic fillers of polyaniline (PANI) and M-type barium hexaferrite (BaM) nanoparticles respectively were incorporated. BaM nanoparticles were synthesized by chemical co-precipitation method. Polyaniline doped with HCl was synthesized by oxidative polymerization of aniline in HCl. Polymer nanocomposite films of Polyaniline and BaM nanoparticles and hybrid polymer nanocomposite films of polystyrene, polyaniline and BaM nanoparticles were prepared by solution casting method. Polymer films were characterized for structural and morphological properties by X-Ray diffraction (XRD) and Scanning electron microscope (SEM), for dielectric properties by impedance analyzer, for EMI shielding properties by vector network analyzer (VNA) and for tensile testing by universal testing machine (UTM). XRD patterns showed that the BaM nanoparticles are exhibiting their own phase in the samples. Scanning electron microscopy revealed the spherical morphology of BaM nanoparticles. SEM analysis also confirmed the successful dispersion of BaM nanoparticles. Dielectric properties of PS were enhanced with the inclusion of BaM nanoparticles and PANI and continued to do so with increasing concentration. Although the hybrid nanocomposite of PS/PANI/BaM showed superior dielectric properties than nanocomposite PS/BaM due to increased heterogeneity. Dielectric properties at 3000 Hz also displayed an increasing trend as a function of temperature. Sample of hybrid nanocomposite with polyaniline and highest concentration BaM nanoparticles was most influenced by the temperature as compared to other samples. Microwave absorption test revealed that with the inclusion BaM nanoparticles and PANI the nanocomposite films and hybrid nanocomposite films developed absorption in X and Ku band and are capable for applications in attenuating radar and satellite communications. Tensile testing showed the decline in overall mechanical strength of the material by incorporating BaM nanoparticles and PANI. The decline is due to the weak wetting at the interfaces between the matrix and fillers.