Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 1From Chemistry to Clinic: Polysaccharide-Bioceramic Composites for Tissue Engineering Applications(Mary Ann Liebert, Inc, 2025) Yakubogullari, Nilgun; Yilmaz-Dagdeviren, Hilal Deniz; Arslan-Yildiz, AhuComposite scaffolds combining polysaccharides and bioceramics represent next-generation scaffolds extensively investigated in tissue engineering (TE) and biomedical applications. Polysaccharides such as chitosan, hyaluronic acid, and pectin mimic the extracellular matrix components with their tunable physicochemical properties, enabling a favorable microenvironment for cell adhesion, proliferation, and cell-matrix interactions. On the other hand, bioceramics, including calcium phosphate, hydroxyapatite, and bioactive glasses, enhance the mechanical properties of the material and offer structural integrity and osteoconductive properties. While they have generally been preferred to be used in bone TE and dental applications, various studies have also demonstrated their potential in cartilage regeneration, wound healing, and broader biomedical applications. Recent advancements in material design and scaffold fabrication techniques, particularly 3D printing and electrospinning, have provided precise engineering of materials and fabrication of scaffolds for desirable mechanical properties and biological performance. These innovations foster the development of patient-specific scaffolds, thereby paving the way for applications in personalized medicine. This review critically summarizes alternative polysaccharides, bioceramics, and composite materials used in TE and biomedical applications. It also highlights advanced fabrication strategies and finally explores the translational potential of these biocomposites. By integrating emerging technologies, this review aims to provide alternative and sustainable materials for the development of next-generation scaffolds that meet clinical needs.Impact Statement This study introduces polysaccharide-bioceramic composites with enhanced mechanical and biological properties for tissue engineering. Beyond bone and dental repair, their applications increasingly extend to wound healing, cartilage, cardiac, and muscle regeneration with drug delivery, angiogenesis, and neurogenesis. By mimicking the native extracellular matrix, these composites support cell growth and tissue regeneration, offering a versatile platform for advanced regenerative therapies.Article Citation - WoS: 9Citation - Scopus: 13Analysis of Adhesively Bonded Joints of Laser Surface Treated Composite Primary Components of Aircraft Structures(Elsevier, 2023) Martin, Seçkin; Nuhoğlu, Kaan; Aktaş, Engin; Tanoğlu, Metin; İplikçi, Hande; Barışık, Murat; Yeke, Melisa; Türkdoğan, Ceren; Esenoğlu, Gözde; Dehneliler, SerkanThe performance of the adhesively bonded aerospace structures highly depends on the adhesion strength between the adhesive and adherents, which is affected by, in particular, the condition of the bonding surface. Among the various surface treatment methods, as state of the art, laser surface treatment is a suitable option for the CFRP composite structures to enhance the adhesion performance, adjusting the roughness and surface free energy with relatively minimizing the damage to the fibers. The aim of this study is the validation and evaluation of the adhesive bonding behavior of the laser surface-treated CFRP composite structures, using the finite element technique to perform a conservative prediction of the failure load and damage growth. Such objectives were achieved by executing both experimental and numerical analyses of the secondary bonded CFRP parts using a structural adhesive. In this regard, to complement physical experiments by means of numerical simulation, macro-scale 3D FEA of adhesively bonded Single Lap Joint and Skin-Spar Joint specimens has been developed employing the Cohesive Zone Model (CZM) technique in order to simulate bonding behavior in composite structures especially skin-spar relation in the aircraft wing-box.Article Citation - WoS: 8Citation - Scopus: 8Design and Fabrication of Polymer Micro/Nano Composites With Two-Level Mechanical Reinforcing Procedure(Wiley, 2022) Kandemir, Ayşe Çağıl; Dönmez, Fatma; Davut, Kemal; Kaplan Can, HaticeBiocompatible composite production was accomplished by utilizing two-level hierarchical approach for mechanical reinforcement. A well-known commodity polymer; low-density polyethylene (LDPE), which has high-fracture toughness, yet low strength and modulus was used as the main matrix material. As the first step of hierarchy, ductile LDPE was blended with brittle polyvinylpyrrolidone (PVP), which is an eco-friendly, nontoxic and biocompatible polymer. This resulted in slight decrease of strength and drastic reduction of toughness (%70), yet modulus was increased by 78%. As the second level of hierarchy, PVP composites were introduced in LDPE. Nano-scaled Halloysite clay and micro-scaled spherical Silica particles were utilized as additives in the aforementioned PVP composites. The reason for the choice of these particles is that they are nontoxic, low-cost and in the case of Halloysite; abundant in nature. Owing to the implementation of the second level; modulus improvement was further enhanced to 150%, with additional benefits of strength increase up to 17% and less reduction in fracture toughness (minimum 51% reduction). Dynamic mechanical analysis also supported these outcomes that storage modulus of composites are higher than both LDPE and LDPE-PVP blend. The proposed biocompatible composites in the end of this study would be utilized in biomedical applications necessitating mechanical improvements.Article Citation - WoS: 61Citation - Scopus: 64Electrospun Gelma Fibers and P(hema) Matrix Composite for Corneal Tissue Engineering(Elsevier Ltd., 2021) Arıca, Tuğçe A.; Güzelgülgen, Meltem; Yıldız, Ahu Arslan; Demir, Mustafa MuammerThe development of biocompatible and transparent three-dimensional materials is desirable for corneal tissue engineering. Inspired from the cornea structure, gelatin methacryloyl-poly(2-hydroxymethyl methacrylate) (GelMA-p(HEMA)) composite hydrogel was fabricated. GelMA fibers were produced via electrospinning and covered with a thin layer of p(HEMA) in the presence of N,N?-methylenebisacrylamide (MBA) as cross-linker by drop-casting. The structure of resulting GelMA-p(HEMA) composite was characterized by spectrophotometry, microscopy, and swelling studies. Biocompatibility and biological properties of the both p(HEMA) and GelMA-p(HEMA) composite have been investigated by 3D cell culture, red blood cell hemolysis, and protein adsorption studies (i.e., human serum albumin, human immunoglobulin and egg white lysozyme). The optical transmittance of the GelMA-p(HEMA) composite was found to be approximately 70% at 550 nm. The GelMA-p(HEMA) composite was biocompatible with tear fluid proteins and convenient for cell adhesion and growth. Thus, as prepared hydrogel composite may find extensive applications in future for the development of corneal tissue engineering as well as preparation of stroma of the corneal material. © 2020 Elsevier B.V.Article Citation - WoS: 2Citation - Scopus: 10Water and Water Vapor Sorption Studies in Poly(propylene)-Zeolite Composites(John Wiley and Sons Inc., 2003) Pehlivan, Hilal; Özmıhçı, Filiz; Tıhmınlıoğlu, Funda; Balköse, Devrim; Ülkü, SemraWater and water vapor sorption to porous poly(propylene)zeolite composites prepared by hot pressing have been studied as a function of zeolite loading. This work presents the first report on the effect of the zeolite as a filler on the water sorption properties of PP composites. Water swelling experiments were conducted at 25°C using pure PP and PP-zeolite film samples having different zeolite loadings (6-40 wt%). Since PP is a hydrophobic polymer, it does not sorp any water, but the composites having 10, 20, 30, and 40% zeolite sorbed 0.63, 1.00, 1.72 and 3.74 wt% water, respectively. The zeolite itself at the same conditions sorbed 24.5 wt% water. As the filler loading in the composites increased, equilibrium uptake values increased too. On the other hand, water vapor sorption and kinetics has been studied using a Cahn 2000 gravimetric sorption system. Within in the range 0.35-0.95%, water vapor was adsorbed by the composites containing 10-40 wt% zeolite. Experimental effective water vapor diffusivities of the composite films were about one order of magnitude higher than the experimental water diffusion coefficient in composites. The transport of water in composites was slower than that in the liquid water due to the longer diffusion pathway and adsorption on the surface of the composites. Although the liquid water may fill all the voids in the composite, water vapor is adsorbed on the surface of the zeolite only.Article Citation - WoS: 19Citation - Scopus: 20Isothermal Crystallization Kinetics and Mechanical Properties of Polycaprolactone Composites With Zinc Oxide, Oleic Acid, and Glycerol Monooleate(John Wiley and Sons Inc., 2013) Alp, Burcu; Cesur, SerapThe isothermal crystallization and mechanical behavior of polycaprolactone (PCL) with zinc oxide (ZnO) with oleic acid and glycerol monooleate (GMO) were studied. Theoretical melting points calculated by the Flory-Huggins and Thompson-Gibbs models were thoroughly compared with differential scanning calorimetry experimental observations. The isothermal crystallization kinetic parameters by Avrami analysis showed that crystallization was controlled by nucleation, crystal growth was spherical, and the nucleation type changed between thermal and athermal nucleation. X-ray diffraction showed that when the additives were used together both the crystal thickness and the degree of crystallinity increased. A multiple-response regression analysis was made with the ZnO, oleic acid, and GMO concentrations as variables and the crystallinity as output. Interaction parameters by the Pukanzky model were calculated from the tensile strength at the yield point and indicated that the addition of oleic acid or GMO improved the interface between the ZnO particles and PCL.Article Citation - WoS: 17Citation - Scopus: 21Effects of Particle Size and Electrical Resistivity of Filler on Mechanical, Electrical, and Thermal Properties of Linear Low Density Polyethylene-Zinc Oxide Composites(John Wiley and Sons Inc., 2013) Özmıhçı Ömürlü, Filiz; Balköse, DevrimThe effects of particle size and electrical resistivity of zinc oxide (ZnO) on mechanical properties, electrical and thermal conductivities of composites made with linear low density polyethylene (LLDPE) were investigated. Micron sized (mZnO), submicron sized (sZnO), and nano sized (nZnO) powders having resistivities of 1.5 × 106, 1.5 × 109, and 1.7 × 108 were used to prepare composites with 5-20 vol % filler. The tensile strength was lowered and the modulus of elasticity of the composites was increased with ZnO addition. Rather than the particle size of the ZnO, its initial resistivity and aspect ratio affected the resistivity of composites. The resistivity of the LLDPE was lowered from 2.3 × 1016 Ω cm down to 1.4 × 1010 Ω cm with mZnO addition. Thermal conductivity of the composites was increased with ZnO addition 2.5-3 times of the polymer matrix. The composites can be used for electrostatically dissipating and heat sink applications due to their decreased electrical resistivity and increased thermal conductivity.Article Citation - WoS: 18Citation - Scopus: 19Effect of Zeolite Filler on the Thermal Degradation Kinetics of Polypropylene(John Wiley and Sons Inc., 2006) Pehlivan, Hilal; Balköse, Devrim; Ülkü, Semra; Tıhmınlıoğlu, FundaIn this study, the thermal degradation behavior of polypropylene (PP) and PP-zeolite composites was investigated, Clinoptilolite, a natural zeolitic tuff, was used as the filler material in composites. The effects of both pure clinoptilolite and silver-ion-exchanged clinoptilolite on the thermal degradation kinetics of the PP composites was studied with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Polymer degradation was evaluated with DSC at heating rates of 5, 10, and 20°C/ min from room temperature to 500°C. The silver concentration (4.36, 27.85, and 183.8 mg of Ag/g of zeolite) was the selected parameter under consideration. From the DSC curves, we observed that the heat of degradation values of the composites containing 2-6% silver-exchanged zeolite (321-390 kj/kg) were larger than that of the pure PP (258 kj/kg). From the DSC results, we confirmed that the PPzeolite composites can be used at higher temperatures than the pure PP polymer because of its higher thermal stability, The thermal decomposition activation energies of the composites were calculated with both the Kissinger and Ozawa models. The values predicted from these two equations were in close agreement. From the TGA curves, we found that zeolite addition into the PP matrix slowed the decomposition reaction; however, silver-exchanged zeolite addition into the matrix accelerated the reaction. The higher the silver concentration was, the lower were the thermal decomposition activation energies we obtained. As a result, PP was much more susceptible to thermal decomposition in the presence of silver-exchanged zeolite.Conference Object Citation - WoS: 3Citation - Scopus: 2Fabrication of Superconducting Mgb2 From Boron Oxide (b 2o3), and Its Microstructural and Electrical Characterization(National Institute of Optoelectronics, 2005) Yavaş, Mert; Okur, Salih; Eğilmez, Mehmet; Kalkancı, Mihriban; Özyüzer, LütfiThe discovery of superconducting MgB2 (39 K) draws attention to it as a new material for applications based on superconductivity. Many researchers successfully synthesized MgB2 using commercial boron and magnesium. In this study, elementary boron was obtained via an acid leaching process, after reacting B2O3, and Mg in an argon atmosphere at 800°C. Energy Dispersive X-ray Spectroscopy (EDX) results revealed that the powder obtained from the reaction was boron in 92% purity with magnesium as the major impurity. Superconducting MgB2 was produced from this boron and magnesium, in an argon atmosphere at 900°C, by a conventional solid-state reaction. Superconducting MgB2 powders were compressed in a dye to pellets by a hot pressing technique at 500°C and 1 GPa. The microstructural properties of the MgB2 were determined by X-ray Diffraction Spectroscopy, EDX, and Scanning Electron Microscopy techniques. The electrical properties of the fabricated MgB 2 were examined by resistivity measurements in a closed-cycle cryopump system, between 20 and 300 K. The critical temperature (Tc) of the MgB2 pellets was around 32 K.Conference Object Citation - WoS: 6Citation - Scopus: 5Electrical and Microstructural Properties of Superconducting Mgb 2/Mg Composites(Trans Tech Publications, 2004) Eğilmez, Mehmet; Günel, Aylin; Okur, Salih; Tanoğlu, Metin; Özyüzer, LütfiMgB2/Mg composites were prepared to improve mechanical properties of brittle superconducting MgB2. MgB2 and Mg powders were mixed at different weight ratios and uniaxially pressed in a cylindrical dye at 0.5 GPa and at various temperatures for two hours to prepare MgB2/Mg composites. X-ray diffraction, SEM and EDX were used for phase identification and microstructural characterization. In addition to the main MgB2 and Mg phases, the microstructural studies have indicated the presence of a minor amounts of second phases, namely MgO and B-rich compounds. The surface morphology, grain size and porosity ratio of the samples prepared under various temperatures were also investigated. The resistivity measurements were performed in the range of room temperature to 15 K. The effect of excess Mg and secondary phases on critical temperature of MgB2/Mg composites were studied.