Investigations on Electromagnetic Interference Shielding Behaviour of Graphene Based Polypyrrole Nanocomposites

Abstract

The electromagnetic interference (EMI) shielding of different electronic gadgets have attracted a lot of attention due to its various applications in industries, defence and electronic communication. The electromagnetic interference present in theenvironment through different possible ways may also affect the human health. Therefore, essentiality of EMI shielding has also been considered for checking the electromagnetic pollution. In order to attenuate the electromagnetic radiation, a shielding material is required. The electromagnetic shielding is done bythree ways i.e. reflection, absorption and multiple reflection. The ability of a material to attenuate the intensity of electromagnetic wave is given by shielding effectiveness (SE). The total SEgreater than 30 dB corresponds to 99.9 % attenuation of microwave radiation and is useful for various defence, military applications. Metals, ceramics and various other composites have been investigated in the quest of vary good EMI shielding materials. These composites have several advantages such as low cost, easy to process, free from corrosion etc. Thereare several frequency bands of microwave defined by Radio Society of Great Britain (RSGB) such as L, C, X, Ku band etc., which are important for different specific purposes ranging from defence to atmospheric science, microwave communication to checking of environmental pollution etc. The X-frequency band of microwave (8.2-12.4 GHz) is useful for many commercial and military application such as Dopplerweather radar, TV transmissionetc. These applications require high shielding due to absorbing along with decreased shielding due to reflection. The materials having high dielectric permittivity and high magnetic permeability may having very good microwave absorbing properties by virtue of presence of electric and magnetic dipoles.