Development and characterization of epoxy matrix nanocomposites for electromagnetic shielding applications

During and after the Second World War, the developing technology, the use of electronic devices, increasing radio wave broadcasts, transistors, systems and equipment such as microprocessors had expanded the frequency spectrum; and unexpected problems has started to occur in the operation of the devices. It was predicted that these problems were caused by the interference of electromagnetic fields that are intentionally and unintentionally emitted from devices and systems. Upon these, the International Electrotechnical Commission (IEC) assigned the International Radio Interference Special Committee (CISPR) to work on the Electromagnetic Interference (EMI) problem. With the establishment of the Federal Communications Commission (FCC) in 1979, the definition of Electromagnetic Interference and the standards and regulations on the subject began to be formed, and the determination of Electromagnetic Compatibility (EMC) criteria accelerated. Nowadays, EMI/EMC issue which is also studied by organizations such as ICNIRP, ANSI, IEEE, ASTM and WHO is important both for the successful operation of the devices and equipment during their service period and for the protection of the health of human and other biological species. Therefore, it is controlled via International Standardizations and regulations. In our country, the relevant regulations and limit values are followed by the Bilgi Teknolojileri ve İletişim Kurumu (BTİK) and the National Monitoring System (MMS). According to the definition of BTİK, the term EMI refers to any broadcast or electromagnetic effect that hinders any system/device activity, interrupts communication or impairs its quality. EMC tests and the issues such as determining whether the device does not cause any interference in the environment as a result of tests, and the presence of CE certificate are essential for devices, equipment and systems, especially telecommunication products. Electromagnetic Interference Shielding has vital importance in the Aerospace and Defense Industry. It is very critical to protect products containing electronic components, circuits, especially precision guidance systems, sensors and actuators against intentional electromagnetic interactions caused by natural, artificial, indirect or international factors. In this context, developing composite materials, additives and processes that have high EMI Shielding Efficiency (EMI SE) is one of the main goals in the material technologies field. In this thesis, the Development and Characterization of Epoxy Matrix Nanocomposites for Electromagnetic Shielding Applications has been studied. When it comes to materials and method, Graphene encapsulated Nickel (GNi) particles were synthesized by the Rotating Plasma-Enhanced Chemical Vapor Deposition (RPECVD) method. After the characterization processes of the particles, the obtained GNi structures were integrated into the epoxy matrices. The nanocomposite structure was obtained and the test coupons were produced. The Shielding Efficiency (SE) of test coupons prepared in different filling percentages was measured. Due to graphene encapsulation, the shielding efficiency of nickel powders improved at the same percentages. SE measurements were conducted in accordance with the ASTM D4935 Electromagnetic Shielding Efficiency test method of Planar Materials for the frequency range 1.5 Ghz-10 GHz. GNi powders have been shown to have potential for use in EMI Shielding applications in epoxy matrix nanocomposite materials for Defense Industry applications. This thesis study were supported by the 118F491 coded project and 118F492 coded subproject within the scope of TUBITAK 1003 program.