Synthesis and Evaluation of Electromagnetic Interference Shielding of Hybrid Polyamide 6/Zirconia Nanoparticles sheets fabricated via Electrospinning Method

نوع: Type: thesis

مقطع: Segment: masters

عنوان: Title: Synthesis and Evaluation of Electromagnetic Interference Shielding of Hybrid Polyamide 6/Zirconia Nanoparticles sheets fabricated via Electrospinning Method

ارائه دهنده: Provider: reyhaneh rezaei

اساتید راهنما: Supervisors: Dr. Hamid Esfahani

اساتید مشاور: Advisory Professors: Dr. Hamid Reza Karmi

اساتید ممتحن یا داور: Examining professors or referees: Dr. Kazemi, Dr. Shahbazi

زمان و تاریخ ارائه: Time and date of presentation: 2023

مکان ارائه: Place of presentation: Conference room of the Faculty of Engineering

چکیده: Abstract: One of the important challenges of electrical and electronic systems is the interference of electromagnetic waves (EMI) caused by factors such as wireless devices, high voltage electrical systems and waves emitted from communication devices which disrupts their performance. One of the ways to overcome this challenge is to use polymer hybrid nanocomposites containing ceramic nanoparticles that can absorb and isolate electromagnetic waves. In this regard, in the present research, nanostructured composite sheets based on polyamide 6 (PA6) containing zirconia (ZrO2) and zinc oxide (ZnO) nanoparticles were produced by electrospinning method and its microstructural, electrical and electromagnetic shielding properties were investigated. For this purpose, the microstructure and diameter size distribution of nanofibers measured by field emission scanning electron microscope (FE-SEM) as well as the chemical composition and crystal structure of these nanofibers by energy diffraction spectroscopy (EDS), elemental analysis map, X-ray diffraction technique (XRD) and Raman spectroscopy were investigated. Also, inductance meter, capacitor meter and resistance meter (LCR) were used to measure the dielectric coefficient and a vector network analyzer (VNA) was used to evaluate the effectiveness of electromagnetic shielding (according to ASTM D4935 standard). The presence of zinc and zirconium elements in nanocomposites containing was proved by Raman tests, EDS and elemental analysis map. Also, according to the results of the microscopic test, the average diameter of the produced fibers for samples without additives and containing nanoparticles of zirconium oxide and zinc oxide were 0.205 ± 0.032, 0.201 ± 0.068, and 0.517 ± 0.032, respectively. It was 0.149 micrometers. The results showed the proper dispersion of zirconia nanoparticles in the polymer matrix and confirmed the dispersion in the agglomerate form for zinc oxide. Also, the diameter size distribution of wide fibers was observed in the sample containing these nanoparticles. The results of the XRD test also indicated the presence of hexagonal ZnO and monoclinic ZrO2 crystal structures in the matrix of nanocomposites with crystal sizes of 28.5 and 24.7 nm, respectively. The average value of the dielectric coefficient in the range of 0.1 to 2 kHz for PA6 sample and nanocomposites containing ZrO2 and ZnO nanoparticles was obtained as 5.89, 11.03 and 11.39, respectively, which shows a higher protective properties for samples containing nanoparticles. Examining the behavior of shielding electromagnetic waves by the S11 signal showed that the effective value of the PA6-ZrO2 sample was higher than the sample without nanoparticles and the PA6-ZnO sample, and the highest effectiveness of this sample was at a frequency of 2.67 GHz (approximately equal to 20 dB). This behavior is due to the proper dispersion of zirconia nanoparticles within the nanofibers. It was also observed that in some frequencies, the efficiency of electromagnetic shielding was very low and close to zero, which indicated the ability of these nanostructured sheets to use as a smart cover to absorb waves at specific frequency ranges and pass some waves in other frequencies

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