Özkaragöz, Nadire Nazlı
Ferroelectric materials are used in different applications because of their superior electrical and dielectric properties. Ferroelectric materials are polarized when an electrical field is applied to the material. This spontaneous polarization continues even if an electrical field is removed. BST (Barium Strontium Titanate) is one of the attractive ferroelectric materials which has a high dielectric constant and low dielectric loss tangent (tanδ). High dielectric constant and low loss tangent are necessary for tunable microwave applications, particularly at X/C band frequencies. Nevertheless, monolithic BST ceramic is not a proper material for electronic applications especially when conformality is required. To eliminate this deficiency of the BST ceramics, BST particle containing polymer matrix composites (BST/PS) providing unique properties can be developed. In the current study, effect of different parameters on the characteristics and tunability performance of the dielectric properties of the BST particle containing polymer matrix composites has been investigated. BST particle size, particle size distribution and content in the composites have been determined to be the key parameters effective on the tunability potential of such composites. Within the scope of this study, it was concluded that tunability potential of the BST/PS composites improves with increasing content of the fine-sized BST ceramics having Ba/Sr/Ti molar ratio of 0.7/0.3/1 which increases further at higher applied bias voltage.


Bahtiyar, Doruk; Aydınol, Mehmet Kadri; Department of Metallurgical and Materials Engineering (2022-9)
For many years, materials in the form of metal sulfides, oxides, phosphates, and titanates have been developed as cathode and anode active materials to be used in energy storage devices. Borides and borates, recently, attracted the attention of researchers in this field. In this study, for the development of a new class of materials for energy storage applications, synthesis and characterization of metal (Fe, Mo, Mn, and V) borides and (Mn, and Y)borates were carried out. The obtained materials were tested ...
Development of novel immobilization matrices via surface modification approach for glucose detection and their biosensor applications
Demirci Uzun, Sema; Toppare, Levent Kamil; Timur, Suna; Department of Polymer Science and Technology (2014)
Biosensors which include biorecognition element and the transducer are widely used devices in many research areas. In an electrochemical biosensor construction, immobilization of redox enzymes on conductive surfaces is a crucial step to obtain stable electrodes. The use of conducting polymers as appropriate immobilization matrices for biomolecules leads to the improvement of biosensors as economical tools for clinical and pharmaceutical analyses. In that manner, electrically conducting polymers can be depos...
Development andcharacterization of activated carbon / transition metal phosphide composites for electrochemical capacitors
Köse, Kadir Özgün; Aydınol, Mehmet Kadri (null; 2019-09-11)
Electrochemical capacitors are the energy storage devices based mainly on electrical double layer formation. Their power densities are exceptionally high; however, their energy densities are characteristically low to compete various types of batteries in market. Therefore, there have been great amount of studies to enhance electrochemical capacitors’ energy density. Utilization of inorganic materials such as transition metal oxides and/or phosphides is one of the most common strategies to increase energy de...
A 5-Parameter Isothermal Creep Model For Polymeric Liners
Güner, Doğukan; Öztürk, Hasan (null; 2019-07-12)
Polymeric materials are commonly used as load-carrying components in different structural applications due to the ease of manufacture, installation and long lifetime properties. In civil and mining engineering applications, fast-setting thin polymeric liners are in demand as areal support elements in underground openings. The stability of the openings is maintained by polymeric liners that might sustain the constant loads due to the presence of wedge blocks. Therefore, their time-dependent mechanical respo...
Synthesis of acrylic based high internal phase emulsion polymers and their application in chromatography
Tunç, Yeliz; Hasırcı, Nesrin; Department of Polymer Science and Technology (2009)
High internal phase emulsion polymers (PolyHIPEs) are new generation materials with their high porosity and interconnected open-cell structures and finds applications in areas such as supports for catalytic systems, separation media and tissue engineering scaffolds. Styrene based PolyHIPEs are currently the most popular choice, but solvent compatibility and poor mechanical properties of these materials prevent their applications. Therefore development of new polyHIPEs with desired mechanical and cellular pr...
Citation Formats
N. N. Özkaragöz, “DEVELOPMENT OF POLYMER MATRIX COMPOSITES WITH TUNABLE DIELECTRIC PROPERTIES,” M.S. - Master of Science, Middle East Technical University, 2022.