Enhanced microwave absorption and suppressed reflection of polypyrrole-cobalt ferrite-graphene nanocomposite in X-band

Polypyrrole-cobalt ferrite-graphene (PCG) nanocomposites have been synthesized by in-situ chemical oxidative polymerization. The effect of graphene loading in nanocomposite on shielding effectiveness, dielectric permittivity, magnetic permeability, ac conductivity and skin depth has been studied in X-band (8.2-12.4 GHz). PCG nanocomposite shows highest shielding effectiveness by absorption similar to 37 dB and least reflection < 1 dB. Enhanced microwave absorption in nanocomposite is attributed to increased dielectric loss due to increase in interfacial polarization and formation of conducting network in composite. Mechanism of shielding effectiveness by various processes i.e. reflection, absorption, multiple reflections etc. is also illustrated. Substantially, enhanced absorption and decreased reflection may be useful in defence for stealth technology in aerospace and, for internal application in cavity for reducing the internal oscillations. (C) 2019 Published by Elsevier B.V.