Araştırma Çıktıları / Research Outputs

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Design and Synthesis of Novel Compounds Based on Dithienylpyrrole Systems Containing Azobenzene Units and Their Electrochemical and Optical Properties as well as Their Processable Conducting Polymers
Chemical Engineering
Two dithienylpyrroles based on azo dyes, namely 2,5’-dimethyl-[4-(2,5-di-thiophen-2-yl-pyrrol-1- yl)-phenyl]azobenzene (1) and 2,5’-dimethyloxy-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl] azobenzene (2), were synthesized and their corresponding polymers (P1 and P2) were successfully obtained via electropolymerization. The monomers have lower oxidation potentials (0.75 V and 0.80 V vs. Ag/AgCl for 1 and 2, respectively) when compared to their analogous. Both monomers exhibited photoisomerism properties under irradiation at 360 nm. During the irradiation process, for example, the color of monomer 2 changes from yellow to greenish yellow. The electroactive polymer films have well-defined and reversible redox couples with a good cycle stability in both aqueous and organic solutions. The polymer films also exhibited electrochromic behaviors; color changes from yellowish green to dark green for the P1 (λma= 435 nm and Eg= 2.31 eV) and from mustard color to green for P2 (λmax= 430 nm and Eg= 2.34 eV). Furthermore, the soluble polymers demonstrated different hues of yellow and green colors. The electrochemical and optical properties of a novel conducting copolymer called poly(3,4- ethylenedioxythiophene-co-1)-(P(EDOT-co-1)) are reported. Electrochemically synthesized P(EDOTco- 1) based on the azo dye has a well-defined and reversible redox couple (0.37 V vs. Ag/AgCl) with good cycle stability. The copolymer film exhibits high conductivity (13 S/cm) as well as electrochromic behavior (magenta when neutralized and transmissive sky blue when oxidized). Furthermore, electrooptically active copolymer film has a low band gap of 1.79 eV with a π−π* transition at 555 nm.
Geri Kazanılmış PET/PEN Karışımlarının Özelliklerinin Farklı Zincir Uzatıcılar Kullanımı ile İyileştirilmesi
PET/PEN mixtures have been studied extensively in the literature for the production of materials with economically viable and superior properties. However, as it is known, PET and PEN are not compatible polymers with each other and various methods are used to harmonize these mixtures. One of these methods is the transesterification reaction of PET and PEN during mixing from the melt. However, during transesterification, the molecular weight of polymers decreases by exposure to thermal, hydrolytic and oxidative degradation. Adding chain-extending chemicals to the mix to reduce this effect is one of the methods used. In this study, the effect of 1, 4 phenylene bis, oxazoline (PBO), tri phenyl phosphate (TPP) and 1, 4 phenyl diisocyanate (PDI) chain extenders on the properties of PET/PEN mixtures prepared with recycled PET (r-PET) was investigated. First of all, the effect of PEN amount on r-PET-PEN mixtures was examined and 70/30% r-PET-PEN mixture was determined as control sample. Later, chain extenders of 0.5, 1.0 and 2.0 wt.% were added to this composition. Tensile and impact tests were performed to examine the effect of chain extenders on the mechanical properties of r-PET-PEN mixtures. Differential scanning calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were used to determine the glass transition temperature. The level of the transesterification reaction was calculated using the Nuclear Magnetic Resonance Spectroscopy (H1-NMR) technique. In the light of all these data, it was determined that PDI was the most suitable chain extender for r-PET-PEN mixtures, while TPP was not a suitable chain extender for this mixture.
Lityum-Iyon Pilde Bir Anot Olarak Katmanlı Titanyum Karbürün Ilk Prensip Çalışması
Metallurgical and Materials Engineering
There is an urgent need to find an anode material with excellent structural and electrical properties, high rate capability, and high capacity for use in Li-ion batteries. Mxene structured TiC3 can be proposed as a potential anode material for Li-ion batteries. This project aims to investigate the mechanical, thermal, and electronic properties of the TiC3 bilayer through Density Functional Theory (DFT) calculations.
Multipl Skleroz Hastaları ile Bakımverenlerinin Psikolojik Belirti Düzeyleri, Sorun Alanları ve İhtiyaçları Açılarından Değerlendirilmesi
Department of Psychology
Multiple Sclerosis (MS) is a degenerative nervous system disorder which results from demyelinazation. The disorder whose etiology is not fully understood and which cannot be cured influences the person’s psychological health, daily lives and relationships, as well as their physical health. The aim of the current study is to investigate the adjustment to illness process, identify the needs, problems and psychological symptom level and its predictors of both the patients and their caregivers. To fulfill this aim, bu using both qualitative and quantitative method, information gathered from 40 MS patients and their caregivers is evaluated. Semi stuructured interviews were conducted and scales were administered measuring MS symptoms, health locus of control, ways of coping, caregiver well-being psychological symptoms. Results of the qualitative analysis revealed physical disability and illness symptoms, difficulties with social life, anxiety about the future and illness representations themes for the problems of patients. The needs of the patients were faith, social support and material needs. For the caregivers, the problems were illness symptoms, anxiety about the future and limitations of social life; whereas the needs were material, information and support and help. The results of the quantitative analyses revealed that as the level of physical symptoms increases, and the use of problem focused coping decreases, the level of psychological symptoms inceases. For the caregivers, as the level of fulfilling basic needs increases, as the use of problem focused coping decreases and as the use of emotion focused coping increases; the level of psychological symptoms inceases, too. Combining the qualitative and quantitative results, the themes specific to the patients whose level of psychological symptoms are high, were loneliness and rejection, for the caregivers negative point of view and rigidity. The results of the current study has important implications in terms of including both caregivers and the patients to the research focusing on chronic illnesses, as well as guidance for the psychosocial interventions for chronically ill people and their caregivers

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