451 Parveen Saini (ed.) Fundamentals of Conjugated Polymer Blends, Copolymers and Composites, (451–518) © 2015 Scrivener Publishing LLC 9 Intrinsically Conducting Polymer- Based Blends and Composites for Electromagnetic Interference Shielding: heoretical and Experimental Aspects Parveen Saini CSIR-National Physical Laboratory, New Delhi, India Abstract he proliferation of miniaturized electronics and prevalence of transient power source have produced electromagnetic interference (EMI) an ofshoot. he inter- ference among electronic instruments or gadgets may lead to deterioration of performance. Recently, conducting polymer-based blends and composites with unique combination of electrical, dielectric, magnetic, and/or mechanical proper- ties have emerged as powerful solution for handling EMI issue. his chapter gives an overview of fundamentals of EMI shielding, theoretical aspects of shielding, and experimental techniques for measurement of shielding efectiveness followed by detailed discussion on potential EMI shielding materials with main emphasis on intrinsically conducting polymer-based blends and composites. he chapter concludes with current challenges and prospects of these hybrids. Keywords: Electromagnetic interference (EMI) shielding, microwave absorp- tion, electrical conductivity, nanocomposites, intrinsically conducting polymers (ICPs), polyaniline, carbon nanotubes, graphene, shielding efectiveness, relec- tion loss, absorption loss, complex permittivity and permeability 9.1 Introduction Electromagnetic (EM) interference (EMI) is an ofshoot of proliferation of electronics and wireless technology, which may be considered as a Corresponding author: pksaini@nplindia.org