PROGRESS AND CHALLENGES IN DEVELOPING ELECTROMAGNETIC INTERFERENCE MATERIALS EMI Shielding Characteristics of Electrically Conductive Polymer Blends of PS/PANI in Microwave and IR Region MUHAMMAD FAYZAN SHAKIR, 1 IQRA ABDUL RASHID, 1,2 ASRA TARIQ, 1,3 YASIR NAWAB, 1 AYESHA AFZAL , 1,4 MUHAMMAD NABEEL, 1 AHMAD NASEEM, 1 and USAMA HAMID 1 1.—Polymer Engineering Department, National Textile University, Faisalabad, Pakistan. 2.—e-mail: iqra.rashid@ntu.edu.pk. 3.—e-mail: asra.tariq@ntu.edu.pk. 4.—e-mail: ayeshaafzal91@yahoo.com Conductive polymeric blends (CPBs) of polystyrene and polyaniline (PS/PANI) were prepared by solution casting method in various compositions. Film thickness of CPBs was achieved  250 micron. PS/PANI blend films were analyzed for electromagnetic interference (EMI) shielding characteristics in microwave and near-infrared (NIR) regions. PS/PANI blends showed remarkable features. Most mobile telecommunications use GHz frequency range and shielding effectiveness was observed in 9 GHz to 18 GHz. In 9 GHz to 18 GHz frequency range, 45 dB shielding effectiveness was measured. CPBs were also analyzed in the NIR region and showed transmittance of <1%. Microwaves and NIR radiation are the most abundant in the environ- ment and cause damage to human health. Both types of radiation causes serious damage to electronic devices as well. Key words: Polyaniline, electrically conductive polymer blend, EMI shielding, IR blocking INTRODUCTION Electromagnetic interference (EMI) shielding acts as a barrier between the device and electromagnetic radiation. Electromagnetic interference diminishes the performance and life of the devices. 1 EMI shield is a coating on an electronic device which consists of conducting materials, for example, aluminum, cop- per and steel, however, nowadays polymeric coat- ings are in use. 2–5 A 50 dB shielding was reported using polyvinylidene fluoride/graphite composite using 70 wt.% of graphite flakes. 6 Reduced gra- phene oxide (rGO) anchored Ni-Co-Zn-Nd-ferrites. Polyaniline has been used and evaluated for 70 dB EMI shielding. 7 Polyaniline/graphene-based com- posite ink was prepared with 1 mm thickness that seemed to have attenuation of 70 dB whereas at lower thickness of 50 lm the shielding was observed at 17 dB. 8 Nylon and cotton-based fabric were prepared with incorporation of PANI nano-particles with thickness of 0.1 mm that gave 15 dB shielding effectiveness. 9 A four-component system based on PANI, carbon nanotube, graphene and epoxy were already prepared and evaluated that showed 45 dB of shielding effectiveness with shield thickness of 0.1 mm. 10 A three-component system of polyvinyl chloride/PANI/Graphene was with 15 wt.% PANI and 5 wt.% graphene were prepared and found out to have 52 dB shielding effectiveness. 4 Moreover, PANI is also being used in stretchable biosensors. 11 Conducting polymer materials are preferred over conventional metals, i.e., aluminum, copper and steel because of flexibility, lightweight, corrosion resistance and ease of processability. Moreover, conductive polymers were found easy to blend with other polymers with more flexibility and robust thermoplastics. Different blends of elastomeric poly- mers with conducting polymers were fabricated. (Received June 12, 2019 ; accepted September 7, 2019) Journal of ELECTRONIC MATERIALS https://doi.org/10.1007/s11664-019-07631-7 Ó 2019 The Minerals, Metals & Materials Society