Sundararaj, UttandaramanMende Anjaneyalu, Abilash2019-06-202019-06-202019-06-18Mende Anjaneyalu, A. (2019). Electromagnetic Interference Shielding Effectiveness of Hybrid Polymer Nanocomposites (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.http://hdl.handle.net/1880/110513In recent years, electronics have become pervasive in our society. This has resulted in an increase in electromagnetic (EM) pollution, which has significant impact on many sectors. In order to attenuate the radiation from the EM pollution, extensive investigations are performed with different materials for attenuating this radiation. For EM wave attenuation, conductive polymer nanocomposites (CPN) is a promising candidate due to low cost, lightweight, easy processability, high flexibility and tailoring properties and nanocomposites also attenuates microwaves by absorption mechanism. Using single nanofiller, CPN has shown higher shielding effectiveness with higher fraction of nanofillers and thicker sample size. Dual nanofillers in CPN also help attain good EMI shielding properties, but with lower fraction of nanofillers and thinner sample compared to single nanofillers. This is attributed to the synergetic effect of both the fillers to attenuate the incoming EM waves. In this dissertation, the primary objective is to investigate the effect of secondary fillers in the hybrid polymer nanocomposites on the electrical properties, i.e., electrical conductivity, dielectric and EMI shielding properties. Due to the low mass density, high aspect ratio and lower electrical percolation threshold in the polymer matrix, multiwall carbon nanotubes (MWCNT) were used as primary conductive nanofiller in most of the studies. Various secondary conductive, magnetic and dielectric nanofillers were employed to study the effect of secondary nanofiller properties on EMI shielding performance of polymer-based nanocomposites. Different mixing techniques, such as melt mixing and solution mixing technique were also investigated. The results show that, the addition of secondary nanofillers improves the dispersion quality of the primary nanofillers in both mixing techniques. Additionally, based on geometry and aspect ratio of the secondary nanofillers, the shielding properties of nanocomposites were improved through the synergistic effect associated with hybrid fillers. Using the dual filler approach, CPN showed higher EMI shielding effectiveness (SE) with low filler content and lower thickness, which makes it a potential candidate for numerous commercial applications as microwave absorber.  engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.multiwall carbon nanotubesnanowireshybrid fillersEMInanocompositesEducation--TechnologyChemistry--Polymermaster thesis10.11575/PRISM/36649