Master Degree / Yüksek Lisans Tezleri

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Language: search.filters.language.enSubject: search.filters.subject.Initiated chemical vapor deposition

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  • Master Thesis
    Fabrication of Polymeric Nano-Coatings Via Chemical Vapor Deposition
    (Izmir Institute of Technology, 2016) Kırköse, Sema; Ebil, Özgenç; Ebil, Özgenç; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Thin film coatings are used to provide protection to the substrate of interest against physical and chemical elements. Coating can also be applied to modify the surface properties of the substrate. One of the most important aspects of coating processes is controlling the thickness of coating material over the substrate. As a subset of a family of chemical vapor deposition methods, iCVD relies on vapor-to-surface reactions to form solid ultrathin polymer films. Unlike other CVD methods, iCVD is unique in that a polymerization reaction is induced by a thermally or chemically activated initiator molecule, much like in liquid-based thermal polymerization except without the use of a liquid solvent medium. The aim of the study is to fabricate polymeric protective nano-coatings via iCVD on flat surfaces at low or ambient temperatures. A variety of polymers, including homopolymers of glycidyl methacrylate (GMA), cyclo hexyl methacrylate (CHMA) and 1H, 1H, 2H, 2H,-Perfluorodecyl acrylate (PFDA) and P(GMA-PFDA) copolymers were fabricated via iCVD. The surface roughness and contact angle values were measured. Smooth hydrophobic surfaces having high contact angle (approximately 130˚) were obtained with PPFDA and PGMA-co-PPFDA thin films. Chemical compositions of the homo and co-polymer films were also evaluated confirming the retention of functional groups during polymerization, thus opening possibility of using iCVD produced films in various sensor applications.
  • Master Thesis
    Development of protective nano-coatings for electro-optical systems
    (01. Izmir Institute of Technology, 2016) Karabıyık, Merve; Ebil, Özgenç; Karabıyık, Merve; Ebil, Özgenç; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Electro-optical (EO) systems have wide range of applications and in recent years, especially the use of EO imaging systems in military and civil aviation applications have substantially increased. In these applications, EO systems are exposed to quite harsh and unstable operating conditions like sudden changes in temperature and humidity, dust, fog, physical shock, vibration and radiation. If their optical surfaces such as prisms, lenses and mirrors are damaged due to these conditions, their repair usually is not possible. To overcome these problems, it is necessary to develop special protective coating layers for optical surfaces. The main goal of this study is to produce protective, self-cleaning and super-hydrophobic polymeric thin films for optical surfaces of the electro-optical (EO) systems. Initiated chemical vapor deposition (iCVD) is a novel method for the fabrication of thin film coatings and it has many advantages such as low production cost, very low deposition temperature, 3D geometry coating performance and high deposition rate. Therefore, iCVD was employed to fabricate homopolymers of poly (glycidyl methacrylate) (PGMA) and poly (1H, 1H, 2H, 2H-Perfluorodecyl acrylate) (PPFDA) and P(GMA-PFDA) copolymer thin-films as protective coatings for EO systems. Optical modeling and simulations were performed to determine the effect of film thickness and refractive index on optical performance of substrates to be coated. Optical performance of fabricated coatings was also measured between 400 and 1000 nm range to confirm that protective coatings do not have any measureable impact on optical performance provided that the protective film thickness is kept between 50 nm to 1 μm. The surface morphology of the protective coatings was evaluated using a variety of analytical tools such as Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Contact Angle measurements. Optical tests were performed by following MIL-F-48616 Military Standard (MIL-STD). The best protective coatings were obtained by using P(GMA-PFDA) copolymer which yields good mechanical properties due to epoxy pendant group and super hydrophobicity due to incorporation of fluoro monomer.