Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Fabrication of Colloidal Photonic Crystals Via Langmuir Blodgett Technique and Their Integration of Polymer Matrix(Izmir Institute of Technology, 2019) İnci, Ezgi; Demir, Mustafa Muammer; Varlıklı, CananColloidal films have potential uses in various fields such as photonics, electronics, sensors, membrane filters, and surface devices owing to their unique optical properties. Photonic crystals composed of uniform diameter colloidal silica particles have been arranged in a periodic structure by taking inspiration from nature. The periodic structure of silica particles has physical interaction with light in a visible range. This special interaction is known as structural coloration. The close-packed monolayers and multilayers of colloidal silica particles in large area can be produced by using Langmuir Blodgett method. The integration of these photonic films with transparent polymer matrices having an elastomer feature provides for their use in optical sensor applications. In this thesis, we examined the fabrication of mechano-sensitive nanostructured films based on colloidal particles. Silica colloidal particles were synthesized at different sizes by using Stöber Process. Langmuir-Blodgett deposition was used to create three-layer of photonic crystal films with different particle diameters. For this purpose, various substrates were examined for the Langmuir Blodgett deposition process before starting the coating. The coated silica particles on the glass substrate were then embedded in an elastomeric transparent matrix. The generation of structural coloration after stretching was examined in manufactured elastomer films. In accordance with this purpose, various polymers such as acrylates and siloxanes with elastomer properties have been used. The structural characterization of these composite films and their optical properties were summarized in this thesis.Master Thesis Integration of Red & Blue Tl Materials To Different Polymer End-Use(Izmir Institute of Technology, 2016) İncel, Anıl; Demir, Mustafa MuammerTriboluminescence (TL) is known as the emission of light upon the application of any mechanical force. In this master thesis, two organometallic-based TL crystals, which are EuD4TEA and Cu(NCS)(py)2(PPh3) were obtained and they were integrated in the transparent polymers: poly (methylmetacrylate) (PMMA), poly (styrene) (PS), poly (urethane) (PU) and polyvinylidene fluoride (PVDF) for different end-use. In the development of composites, two different processes were carried out: i) embedding (or blending) and ii) surface impregnation. The different end-use polymers were used as transparent polymer film, electrospun nanofibers, and nanobeads. TL performance of composites were investigated by using drop tower system which was specficically designed for this research. Atomic force microscopy (AFM), scanning electron microscopy (SEM) were used to characterize the topographic and morphologic properties of both polymers and composites. Additionally, fluorescence microscopy helped to understand the signal of emitted light by composites. Lastly, piezoelectric properties of composite materials were invetigated by oscilloscope. According to results, type of process, particle size of crystal, surface property and form of host material (polymer), the concentration of crystalline particles in composites were determined as the main parameters and the results were estimated with respect to these parameters. PU-based composite film and fiber show better stability towards mechnical stress rather than PMMA, PS, and PVDF due to the roughness surface of thin-film surface for film-based composites, smallest wickerwork formation of electrospun mats for fiber-based composite, and the chemical affinity of PU with TL crystals.