Dielectric and Electromagnetic Interference Shielding Analysis of Conducting Polymer Composites

Abstract

The transformation in the field of science and technology has generated a new kind of pollution known as electromagnetic interference (EMI). EMI not only disturbs the normal operation of electronic appliances but also has adverse effects on human health. This work is dedicated to prepare conducting polymer composites shields to make a device electromagnetic compatible (EMC). EMC means a device does not affect itself or any other device by its electromagnetic (EM) radiation within its electromagnetic environment. Composites are finding an important place for shielding purpose due to their light weight, inexpensiveness, flexibility, chemical and corrosion resistance. The response of composites towards EM radiation can be tailored through the fabrication technique used, electrical conductivity and dielectric properties of the composites. So different types of shield with different fabrication techniques were prepared and there electrical conductivity and dielectric properties were analyzed accordingly. For this purpose, different composites were prepared using PVDF and SAN as an insulating polymer matrix with combination of different kinds of conducting fillers like Graphite (Gr), PEDOT:PSS and Ionic Liquid (IL). The techniques used for fabrication of the shields are compression moulding technique for hard shield and solvent casting method for flexible films. newlineMainly in previous studies the EMI shielding analysis was done in far field region only, the equations used for calculation of shielding were based on planer waves. However, for calculation of the EMISE we must consider the near field region also because generally the SE measurement is made in the near field. This thesis advances the field of EMI shielding with conducting polymer composite by providing the insight on difference in near field shielding and far field shielding. Thesis also emphasise on the effect of conducting filler on dielectric and mechanical properties of the composites.