INTERNATIONAL TECHNOLOGY SCIENCES AND DESIGN SYMPOSIUM, Giresun, Türkiye, 2 - 05 Haziran 2022, ss.28
Phosphorescents emit light during the transition from a triplet system to a singlet system in the ground state, and the radiation continues for a long time after the excitation beams are interrupted. Rare earth elements such as Eu, Sm, Dy are doped to various oxide ceramics to provide them phosphorescence properties. In Eu-doped-SrAl2O3, it radiates as a result of the transition between the 4f-5d energy levels of Eu. In this study, Eu, Sr, and Al nitrate salts and urea (as fuel) were used to obtain phosphorescent powder. H3BO3 acid was added to ensure crystallization. Calculated amounts of nitrates, fuel, and boric acid were added sequentially to distilled water to obtain a clear solution. The prepared solution was placed in a household microwave. The microwave continued to be operated at maximum power until the combustion reaction occurred. The produced powders were then kept in a tube furnace at 900°C for 1 hour to complete the calcination. It was observed that SrAl2O4 was obtained as a result of XRD analysis of the produced powders. Both calcined and non-calcined samples were kept under UV light for 30 seconds and then their luminescence abilities were observed. Then, composite filaments were produced using phosphorescent powders and recycled polymer. Firstly, the polymer, which was ground and granulated by mechanical methods, was mixed with phosphorescent powder in a twin-screw extruder. Later, 1.75 mm diameter filaments were produced with the composite granules in a single screw extruder.