Graphene is a two-dimensional honeycomb material with an atomic-thick planar structure. Graphene is one of the most studied nanomaterials that can be used in nanotechnology applications. There are various methods for synthesizing or isolating graphene monolayers, but by far the most popular uses a process called chemical vapor deposition. Chemical vapor deposition, or CVD, is a process that has the potential to produce relatively high-quality graphene at scale. The CVD process is relatively straightforward with some specialized equipment. However controlling gas volume, pressure, temperature, and timing is critical to producing good quality graphene. In this project, the synthesis of graphene was carried out at different temperatures, pressures and coating times to produce stable, controlled and durable graphene by chemical vapor deposition. The characteristics of graphene sheets obtained by SEM, AFM and Raman spectroscopy analyzes were determined, as well as the optimal parameters for a stable, sustainable and controlled production of graphene. In parallel, the electrical properties of graphene films on different thicknesses have been studied. Therefore, obtaining a thin film with suitable thickness, transmission and electrical properties of graphene, which is currently marketed worldwide, was investigated.

Sonokimyasal reaksiyonlarda, sıvıdaki ultrasonik dalgaların ve kabarcıkların etkileşimi, kimyasal aktivitenin başlaması veya artması gibi birçok olaya neden olabilir. Nano malzemelerin sentezinde akustik kavitasyon sırasında oluşan H ve OH radikalleri bir çok yükseltgenme ve indirgemeleri tetikler. Bu çalışmada, sonokimyasal oluşum ile katalitik ve biyomateryal çekirdek/kabuk morfolojisinin sentezi ve ultrasonik dalga yoğunluğunun biyomalzeme boyutuna etkisi araştırılmıştır. Çekirdek kabuk morfolojisine sahip mikroküreler hazırlamak için yeni bir tek adımlı ultrasonik yöntem geliştirildi. Mikrokürelerin boyutunu ve morfolojisini belirlemek için optik mikroskop, Taramalı Elektron mikroskobu (SEM) kullanıldı. Yüzey morfolojisi, Atomik Kuvvet Mikroskobu (AFM) kullanılarak yeniden incelendi. Sonikasyon süresi 18 dk olarak ayarlandığında istenen mikroküreler elde edildi. Mikrokürelerin kabuğu biyolojik olarak parçalanabilen kitosandır ve çekirdek ZnO nanoparçacıklarıdır. Çekirdek kabuk morfolojisine sahip mikrokürelerin sentezi için geliştirilen reaksiyon yöntemi hızlı ve düşük maliyetlidir.

Pentacarbonyl-N-mercaptopyrimidinemetal(0) complexes of VIB metals (M: Cr, Mo, W) were formed when hexacarbonylmetal(0) complexes are treated photochemically with 4,6-dimethyl-2-mercaptopyrimidine at 10 ºC. The reported organometallic complexes were purified and isolated under an inert atmosphere. All M(CO)5L complexes were characterized in solution by FTIR-, 1H- and 13C-NMR spectroscopies. The FTIR spectroscopy results showed three absorption bands in the carbonyl region which indicates that the pentacarbonyl metal unit of the complexes has a local C4v symmetry. The 1H- and 13C-NMR spectroscopies showed that the mercaptopyrimidine ligand bonded to the metal complex through the mercaptopyrimidine-nitrogen atom symmetrically. The 13C-NMR spectroscopy results also showed a 1:4 ratio of two peaks in the CO-region, the ratio of the peaks proved the C4v symmetry of these complexes. The thermal behavior of these organometallic complexes is investigated by using DTA/TGA methods. The results of thermal analyses showed that the complexes decomposed at three different temperatures. The density functional theory (DFT) calculations were computed in B3PW91 formalism by Gaussian03W Software. The comparison of the experimental data with the theoretical values showed that the results obtained are compatible with each other. Thus, the accuracy of the experimentally given structural proposal of the obtained organometallic complex compounds was also confirmed through theoretical calculations.