Synthesis and characterization of novel doped conducting polymer composites for microwave applications

Abstract

Electromagnetic Interference (EMI) is usually occurring in electronic newlinedevices when exposed to an electromagnetic field, which causes improper newlinefunctioning of the devices. Excess exposure with the electromagenetic radiation newlinecauses cell damage in human being. With the electronic revolution, the ever newlineincreased usage of the electromagnetic spectrum enhanced the need for newlinereducing EMI issues to the more complicated and sophisticated electronic newlinedevices used in the medical and military fields and also prevent human beings newlinefrom hazardous exposure to the electromagnetic radiations. This scenario newlinetriggered the research activities to find a better solution to reduce EMI by newlineabsorbing or reflecting electromagnetic radiation impinging on the destinations. newlineSince the discovery of tunable properties of the conducting polymers, newlinethey are used to create artificially engineered materials which are superior to newlinetraditional metallic counterparts in terms of weight, cost and susceptibility to newlinecorrosion. The use of conducting polymers in many applications produced newlinevarious characteristics that are still under study. EMI shields using conducting newlinepolymers can produce superior electrical, dielectric, thermal, mechanical, and newlinemagnetic properties useful for suppressing electromagnetic impulses. The newlinewideband EMI shields and narrowband absorbers can be designed by newlinemodifying these conducting polymers. newlineIn this thesis work, we have investigated various composites of Polyaniline newlinefor electromagnetic absorption. They include mainly pristine Polyaniline, newlinePolyaniline-Fe2O3 and Polyaniline-CNT samples. Different structures are fabricated newlineand characterized, and the following enhanced properties are observed. newline1. A High EMI shielding of 60 dB is achievable from the lowest thickness newlineof 0.18mm. newline2. A broadband negative permittivity is achievable for thickness newlinedependant film samples. newline3. Anomalous behavior is observed in Polyaniline-CNT based samples. newlineThe characteristics of all the polymer samples are verified by the newlinesimulation tools and experimentally.