Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2025Investigation of mechanical properties of nano-graphene reinforced polymer composites
Karabudak, Filiz; Ateş, Onur Kazım; Zamanlou, Hamid
The demand for lightweight and durable materials in industries such as automotive, aerospace, and chemical engineering has driven research into advanced composite materials. This study investigates the interaction between nano-graphene and polymer matrices, focusing on how varying concentrations of nano-graphene can optimize mechanical properties and potentially revolutionize the design of structural components. Polymer composite materials were produced using glass fiber fabric and an epoxy resin system employing the hand lay-up method. Nano-graphene was incorporated into the matrix at weight percentages of 0.2%, 0.4%, 0.6%, 0.8%, and 1%.Notably, the addition of 1% nano-graphene resulted in a significant tensile strength increase, achieving a maximum value of 186.73 MPa, compared to the control group at 53.71 MPa. This enhancement is attributed to the improved stress transfer mechanisms facilitated by the nano-graphene’s high surface area and exceptional mechanical properties. However, an unexpected decrease in bending strength was observed, with the glass fiber control group composites exhibiting the highest bending strength of 404.75 MPa. This trend suggests that while nano-graphene enhances tensile properties, it may introduce interfacial weaknesses or disrupt fiber alignment in bending scenarios. These findings reveal the complex nature of nano-graphene reinforcement, emphasizing the need for tailored formulations to balance tensile and bending performance. Further investigation into the interfacial bonding and distribution of nano-graphene within the polymer matrix is warranted to develop optimized composite materials for structural applications.
- MakaleYalnız künye2023Wear Behavior of Dental Restorative Materials
Sen, Sadri; Zamanlou, Hamid; Karabudak, Filiz; Süküroglu, Ebru Emine
Gradual wear of opposing teeth is a normal phenomenon in human dentition. There is a need for quality dental restorative materials to repair or replace natural teeth to ensure a higher quality of life through dental health. One of the main physiological mechanism that exists in dental materials during normal muscle function is called abrasion. There are two types of that in teeth which are common; Two-body and three-body. If the teeth are contacted directly, it is referred to as two-body abrasion. However, when there is abrasive slurry-like food between the teeth, this abrasive is called to be three-body abrasive. Several types of materials are available in current dentistry for teeth restoration and replacement, and new materials are being promoted every year. Dental specialists need to understand the wear mechanisms of these new types of dental restorative materials, alone or in combination with either enamel or other dental restorative material. The present study evaluates the abrasive resistance of three restorative materials groups: direct composites, indirect composites, and ceramics. To define the resistance of the wear, the authors then perform a micro-wear test on chosen materials. The results show that the wear mechanism is abrasive due to its low hardness compared to zirconia ball. The wear path in the nanohybrid (Grandio (R), 87s% w/w (71s% volume) inorganic nanohybrid filler, BisGMA, UDMA, TEGDMA) sample was smooth and without particles. In this study wear FEM analysis calculated for all models and the answers compared with experimental data.
- MakaleYalnız künye2018Differential scanning calorimetry (DSC) and Ni+2 release analysis of NiTi-shape-memory dental alloys coated by micro-arc oxidation (MAO) method
Yeşildal, Ruhi; Karabudak, Filiz; Şüküroğlu, Ebru Emine; Şüküroğlu, Süleyman; Zamanlou, Hamid; Bayındır, Funda; Şen, Sadri; Totik, Yaşar
This study aims to prevent the release of Ni+2 and increase the biocompatibility of NiTi-shape-memory dental alloys with the micro-arc oxidation (MAO) coating by preserving the shape-memory feature in the oral environment. The TiO2-ceramic coating and Ag-doped TiO2 coating have been grown on shape-memory, co-atoms’ dental NiTi alloys with the MAO method. Biocompatibility properties of the coating were determined by in-vitro tests. In-vitro tests have been made as retention tests in a simulated body fluid (SBF). Whether the grown surface coating impacts the shape-memory properties of the base material or not has been determined by differential scanning calorimetry (DSC) analysis. It was observed as a result of retention tests that bone-like apatite form occurred on the surface of TiO2-coated NiTi and Ag-doped TiO2-coated NiTi coating. It was determined as a result of retention tests in SBF that the Ni+2 release rate from the base material was below the limit of detection in coated samples. As a result of DSC analysis, it was not observed any significant changes in transformation temperature with the MAO coating. It was concluded that the thin-film coatings formed by MAO technique prevent the release of Ni in the oral environment and increase the biocompatibility by preserving shape memory properties of NiTi dental alloys.
- MakaleYalnız künye2017An Investigation of Corrosion Resistance and Antibacterial Sensitivity Properties of Nano-Ag-Doped TiO 2 Coating and TiO 2 Coating Grown on NiTi Alloy with the Micro-Arc Oxidation Process
Karabudak, Filiz; Yeşildal, Ruhi; Şüküroğlu, Ebru Emine; Şüküroğlu, Süleyman; Zamanlou, Hamid; Dikbaş, Neslihan; Bayındır, Funda; Şen, Sadri; Totik, Yaşar
In this study, TiO 2 coatings were grown with nano-Ag doped and micro-arc oxidation technique on NiTi shape memory alloy. The antibacterial sensitivity and corrosion resistance characteristics of both coatings were investigated. The microstructure and composition analyses of the coatings were performed with scanning electron microscope, energy dispersive X-ray spectrometry, and X-Ray diffraction (XRD). The XRD results showed that there were only TiO 2 crystal phases (anatase and rutile) on the coating. The results showed that a clean and dense oxide layer was grown on the surface successfully. The surface of nano-Ag-doped TiO 2-coated samples appear to be smoother than the surface of the coatings without Ag. The corrosion tests of the coated and uncoated samples were carried out in three different environments (simulated body fluid, synthetic saliva, and cola) at 37 ∘ which is human body temperature. The corrosion tests showed that the corrosion resistance of TiO 2-coated and nano-Ag-doped TiO 2-coated samples was much higher than the corrosion resistance of the NiTi substrate. Seven different bacteria including (S. aureus, L. monocytogenes, Bacillus subtilis, Salmonella enteritidis, Yersinia enterocolitica, and E. coli, P.aeruginosa) which have the human pathogen feature were used in the antibacterial susceptibility tests. The process was conducted based on the disk diffusion method to test the susceptibility of bacterial strains on the selected coated and uncoated samples, and antimicrobial activity was evaluated in the nano-Ag-doped TiO 2-coated material; P.aeruginosa, Y. enterocolitica, and E. coli (zone diameter of 8–14 mm) were found to be moderately susceptible; S. aureus, L. monocytogenes, B. subtilis, and S. enteritidis (zone diameters of 8–14 mm) were found to be resistant. The antimicrobial activity of the coating material NiTi was found to be sensitive for all antibacterial tests. According to the TiO 2-coated material results, S. aureus, P.aeruginosa, L. monocytogenes, E. coli were found to be moderately sensitive and Y. enterocolitica, S. enteritidis, and B. subtilis were found to be resistant.