Polyaniline/oxide-based core-shell like structured composites for reduction in electromagnetic pollution

Abstract

Polyaniline (PANI) based composites with manganese dioxide (MnO2, 30 wt.%) and vanadium pentaoxide (V2O5, 30 wt.%) have been synthesized using the in-situ polymerization synthesis route, whereas both the oxides used as filler materials in the polyaniline matrix. The amalgamated composites have been analyzed for morphological investigation and shielding the incident electromagnetic (EM) waves in the frequency range 8.2-12.4 GHz (X-band). PANI/MnO2 and PANI/V2O5 composites are synthesized in core-shell like morphology, whereas PANI act as core while oxide act as the shell. The shielding of EM waves has been investigated in terms of shielding effectiveness (SE). PANI/MnO2 composite exhibits the efficient SE value i.e. ~50 dB as shown in the figure. This higher value of SE is due to the ferromagnetic character of MnO2 particles which increases the dielectric losses in the specimen. Whereas, PANI/V2O5 composite attain the smaller value of SE i.e. ~9 dB, because V2O5 particles are diamagnetic in nature, thus dielectric losses decrease. Moreover, SE decreases with an increase in frequency due to a decrease in dielectric losses. PANI/MnO2 composite has an SE value greater than the minimum requirement for industrial application i.e. 30 dB, thus, PANI/MnO2 composite can be used as EM shielding material, whereas, PANI/V2O5 composite can’t fulfill this requirement.