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High shielding effect in x-band microwave frequencies of Ferrite-OPEFB-PTFE nanocomposites

Ferrites are the most common materials for microwave absorbing applications that widely used to eliminate undesired or stray radiated electromagnetic signals which could interfere with a system’s operation. This project investigates using the recycled Ferrite (Fe2O3) jointly with biodegradable oi...

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Main Author: Khamis, Ahmad
Format: Thesis
Language:English
Published: 2022
Subjects:
Ferrites (Magnetic materials) - Thermal properties
Microwave heating
Online Access:http://psasir.upm.edu.my/id/eprint/104204/1/FS%202022%2037%20IR.pdf
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spelling oai:psasir.upm.edu.my:104204 http://psasir.upm.edu.my/id/eprint/104204/ High shielding effect in x-band microwave frequencies of Ferrite-OPEFB-PTFE nanocomposites Khamis, Ahmad Ferrites are the most common materials for microwave absorbing applications that widely used to eliminate undesired or stray radiated electromagnetic signals which could interfere with a system’s operation. This project investigates using the recycled Ferrite (Fe2O3) jointly with biodegradable oil palm empty fruit bunch fiber (OPEFB) as fillers and Polytetrafluoroethylene (PTFE) as the host matrix for microwave shielding applications. Hematite (Fe2O3) fillers were recycled from the steel waste (mill scale waste) material and the particle sizes decreased to 11.3 nm after six hours of high energy ball milling. Four different batches of composites were fabricated as follows: Fe2O3-PTFE (batch 1), OPEFB-PTFE (batch 2), OPEFB-PTFE (batch 3), and Fe2O3-OPEFB-PTFE (batch 4) composites. The materials composition, complex permittivity, complex permeability, scattering parameters, density, structural, thermal, and tensile properties of prepared samples were investigated. The COMSOL software based on finite element method (FEM) was used to calculate the scattering parameters and visualize the electric field distribution in the nanocomposites. The coefficient of thermal expansion (CTE) of PTFE sample and 25%Fe2O3 (A) nanocomposite was respectively 65.28×10-6/ ᵒC and 39.84×10-6/ ᵒC, therefore, the recycled Fe2O3 nanofiller enhanced the thermal properties of the nanocomposites. The density increased from 2.2 g/cm3 to 2.54 g/cm3 when the content of Fe2O3 increased from 5 wt.% to 25 wt.% while it decreased from 2.08 g/cm3 to 1.5 g/cm3 when OPEFB increased 5 wt.% to 25 wt.%. At 10 GHz, the complex permittivity of Fe2O3-PTFE nanocomposites increased from (2.2 – j × 0.10) to (3.1 – j × 0.22), while, the complex permeability increased from (1.03 – j × 0.017) to (1.1 – j × 0.038) when the percentage of Fe2O3 increased from 5% to 25%. The transmission coefficients |S21| of the nanocomposites decreased with increasing Fe2O3 content. The |S21| values of Fe2O3-OPEFB-PTFE nanocomposites ranged from 0.84 to 0.62, while, the values of Fe2O3-PTFE nanocomposites varied from 0.86 to 0.74 at 8.2 GHz. The |S11| values of Fe2O3- OPEFB-PTFE nanocomposites ranged from 0.52 to 0.63, while, the values of Fe2O3-PTFE nanocomposites varied from 0.50 to 0.62 at 8.2 GHz. The comparison between the measured and calculated scattering parameters showed a very good agreement. In addition, the total shielding effectiveness (SE) values increased with increasing the content of Fe2O3 nanofiller. At 10 GHz, the range of total SE values for Fe2O3-PTFE nanocomposites was from 12.8 dB to 18.3 dB, while, the range of Fe2O3-OPEFB-PTFE nanocomposites was from 15.6 dB to 19.6 dB. The prepared nanocomposites can therefore be used as promising alternatives for microwave shielding applications due to their shielding effectiveness, low density, low cost, and biodegradability. The recycled Fe2O3 nanoparticles can be used as fillers in polymeric composites for microwave shielding applications due to their low cost, good thermal stability and high shielding effectiveness. 2022-07 Thesis NonPeerReviewed text en http://psasir.upm.edu.my/id/eprint/104204/1/FS%202022%2037%20IR.pdf Khamis, Ahmad (2022) High shielding effect in x-band microwave frequencies of Ferrite-OPEFB-PTFE nanocomposites. Doctoral thesis, Universiti Putra Malaysia. Ferrites (Magnetic materials) - Thermal properties Microwave heating
institution UPM IR
collection UPM IR
language English
topic Ferrites (Magnetic materials) - Thermal properties
Microwave heating
spellingShingle Ferrites (Magnetic materials) - Thermal properties
Microwave heating
Khamis, Ahmad
High shielding effect in x-band microwave frequencies of Ferrite-OPEFB-PTFE nanocomposites
description Ferrites are the most common materials for microwave absorbing applications that widely used to eliminate undesired or stray radiated electromagnetic signals which could interfere with a system’s operation. This project investigates using the recycled Ferrite (Fe2O3) jointly with biodegradable oil palm empty fruit bunch fiber (OPEFB) as fillers and Polytetrafluoroethylene (PTFE) as the host matrix for microwave shielding applications. Hematite (Fe2O3) fillers were recycled from the steel waste (mill scale waste) material and the particle sizes decreased to 11.3 nm after six hours of high energy ball milling. Four different batches of composites were fabricated as follows: Fe2O3-PTFE (batch 1), OPEFB-PTFE (batch 2), OPEFB-PTFE (batch 3), and Fe2O3-OPEFB-PTFE (batch 4) composites. The materials composition, complex permittivity, complex permeability, scattering parameters, density, structural, thermal, and tensile properties of prepared samples were investigated. The COMSOL software based on finite element method (FEM) was used to calculate the scattering parameters and visualize the electric field distribution in the nanocomposites. The coefficient of thermal expansion (CTE) of PTFE sample and 25%Fe2O3 (A) nanocomposite was respectively 65.28×10-6/ ᵒC and 39.84×10-6/ ᵒC, therefore, the recycled Fe2O3 nanofiller enhanced the thermal properties of the nanocomposites. The density increased from 2.2 g/cm3 to 2.54 g/cm3 when the content of Fe2O3 increased from 5 wt.% to 25 wt.% while it decreased from 2.08 g/cm3 to 1.5 g/cm3 when OPEFB increased 5 wt.% to 25 wt.%. At 10 GHz, the complex permittivity of Fe2O3-PTFE nanocomposites increased from (2.2 – j × 0.10) to (3.1 – j × 0.22), while, the complex permeability increased from (1.03 – j × 0.017) to (1.1 – j × 0.038) when the percentage of Fe2O3 increased from 5% to 25%. The transmission coefficients |S21| of the nanocomposites decreased with increasing Fe2O3 content. The |S21| values of Fe2O3-OPEFB-PTFE nanocomposites ranged from 0.84 to 0.62, while, the values of Fe2O3-PTFE nanocomposites varied from 0.86 to 0.74 at 8.2 GHz. The |S11| values of Fe2O3- OPEFB-PTFE nanocomposites ranged from 0.52 to 0.63, while, the values of Fe2O3-PTFE nanocomposites varied from 0.50 to 0.62 at 8.2 GHz. The comparison between the measured and calculated scattering parameters showed a very good agreement. In addition, the total shielding effectiveness (SE) values increased with increasing the content of Fe2O3 nanofiller. At 10 GHz, the range of total SE values for Fe2O3-PTFE nanocomposites was from 12.8 dB to 18.3 dB, while, the range of Fe2O3-OPEFB-PTFE nanocomposites was from 15.6 dB to 19.6 dB. The prepared nanocomposites can therefore be used as promising alternatives for microwave shielding applications due to their shielding effectiveness, low density, low cost, and biodegradability. The recycled Fe2O3 nanoparticles can be used as fillers in polymeric composites for microwave shielding applications due to their low cost, good thermal stability and high shielding effectiveness.
format Thesis
author Khamis, Ahmad
author_facet Khamis, Ahmad
author_sort Khamis, Ahmad
title High shielding effect in x-band microwave frequencies of Ferrite-OPEFB-PTFE nanocomposites
title_short High shielding effect in x-band microwave frequencies of Ferrite-OPEFB-PTFE nanocomposites
title_full High shielding effect in x-band microwave frequencies of Ferrite-OPEFB-PTFE nanocomposites
title_fullStr High shielding effect in x-band microwave frequencies of Ferrite-OPEFB-PTFE nanocomposites
title_full_unstemmed High shielding effect in x-band microwave frequencies of Ferrite-OPEFB-PTFE nanocomposites
title_sort high shielding effect in x-band microwave frequencies of ferrite-opefb-ptfe nanocomposites
publishDate 2022
url http://psasir.upm.edu.my/id/eprint/104204/1/FS%202022%2037%20IR.pdf
_version_ 1782762235411562496
score 12.935284

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