Narayan Ch. Das
The growth in the application of electronic devices across a broad spectrum of military, industrial, commercial and consumer sectors has created a new form of pollution known as radio frequency interference (RFI) or electromagnetic (EM) radiation or EM interference (EMI) that can cause interference or malfunctioning of equipment. Those EM radiation consisting many unwanted radiated signals which not only degrade system or equipment performance, those EM radiation are doing serious effect on human health especially, on nervous system and brain. The possible or suggested effects of EMF on the body are Parkinson's disease, Alzheimer's disease, Cancer, tumors, Headache, fatigue, neurological disorder, etc. One of the simplest methods is to reduce electromagnetic signal by shielding (Fig. 1). Electrical conductive polymeric nanocomposites filled with carbon-based conductive filler are becoming popular for microwave radiation absorbing materials because of their lightweight, high flexibility, anti-corrosive, easy fabrication into intricate shape by common processing techniques and cost-effectiveness. Currently, carbon materials, including carbon fibers, carbon nanotubes (CNTs) and graphene have played a leading role in the investigation and application of microwave absorbing materials due to their low specific mass and high aspect rations, which results in high electromagnetic losses at low filler content along with a reduction of thickness and weight (Fig. 2a-b). In addition, electrical, thermal conductivity, as well as microwave absorbing efficiency or shielding effectiveness, are strongly depends on type of polymer, filler and its concentration, filler dispersion, polymer blends, processing parameter etc