Development and characterization of multifunctional yttrium iron garnet/epoxy nanodielectrics
- PDF / 1,677,187 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 68 Downloads / 190 Views
Development and characterization of multifunctional yttrium iron garnet/epoxy nanodielectrics A. Sanida1 · S. G. Stavropoulos1 · Th. Speliotis2 · G. C. Psarras1 Received: 1 December 2019 / Accepted: 14 September 2020 © Akadémiai Kiadó, Budapest, Hungary 2020
Abstract In the present work, a series of yttrium iron garnet/epoxy nanocomposite systems were fabricated, and the morphology of nanocomposites were tested by Scanning Electron Microscopy. The thermal stability of the developed systems was assessed by Thermogravimetric Analysis; their thermal properties were further investigated via Differential Scanning Calorimetry (DSC) and their viscoelastic response via Dynamic Mechanical Analysis (DMA). Finally, the dielectric characterization was carried out by means of Broadband Dielectric Spectroscopy. DSC curves revealed an endothermic step-like transition of all systems, attributed to the glass to rubber transition of the polymer matrix. All nanocomposites exhibit a two stages degradation profile. The presence of nanoinclusions enhances the thermal stability of the systems shifting the onset of the first degradation process to higher temperatures. Through the DSC and DMA techniques, the transition from glassy to rubbery state of the polymer matrix was observed and the characteristic Tg temperature was determined. The addition of the ceramic inclusions enhances the thermomechanical properties, as well as the dielectric response of the nanocomposites, as implied by the augmenting values of the real part of dielectric permittivity along with the storage modulus with the reinforcing phase loading. Three dielectric relaxation processes were identified: interfacial polarization, glass to rubber transition of the polymer matrix and reorientation of the small polar side groups of the polymer chain at low, intermediate and high frequencies, respectively. Furthermore, the ability of the systems to store energy was examined via the dielectric reinforcing function. Keywords Yttrium iron garnet · Thermomechanical analysis · Dielectric relaxations · Glass transition · Degradation temperature · Energy storage
Introduction Polymeric materials exhibit many attractive properties such as light weight, mechanical strength, thermal stability, anticorrosiveness, and dielectric tunability, all these can be utilized along with ceramic nanoparticles to develop multifunctional materials [1–5]. The electromagnetic response of polymer nanocomposites can be tailored to meet diverse application criteria and depends on various factors like * G. C. Psarras [email protected] Th. Speliotis [email protected] 1
Smart Materials and Nanodielectrics Laboratory, Department of Materials Science, School of Natural Sciences, University of Patras, Patras 26504, Greece
Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Aghia Paraskevim, Athens 15310, Greece
2
permittivity, conductivity, size, shape and volume fraction of the filler, and the dispersion state of the nanoinclusions in the polymer matrix [6–13]. More
Data Loading...
