Materials Science and Engineering / Malzeme Bilimi ve Mühendisliği
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Article Citation - WoS: 4Citation - Scopus: 4Breaking the Boundaries of the Goldschmidt Tolerance Factor With Ethylammonium Lead Iodide Perovskite Nanocrystals(American Chemical Society, 2024) Güvenç, Çetin Meriç; Balcı, Sinan; Toso, Stefano; Ivanov, Yurii P.; Saleh, Gabriele; Balcı, Sinan; Divitini, Giorgio; Manna, Liberato; 04.04. Department of Photonics; 04. Faculty of Science; 01. Izmir Institute of TechnologyWe report the synthesis of ethylammonium lead iodide (EAPbI3) colloidal nanocrystals as another member of the lead halide perovskites family. The insertion of an unusually large A-cation (274 pm in diameter) in the perovskite structure, hitherto considered unlikely due to the unfavorable Goldschmidt tolerance factor, results in a significantly larger lattice parameter compared to the Cs-, methylammonium- and formamidinium-based lead halide perovskite homologues. As a consequence, EAPbI3 nanocrystals are highly unstable, evolving to a nonperovskite delta-EAPbI3 polymorph within 1 day. Also, EAPbI3 nanocrystals are very sensitive to electron irradiation and quickly degrade to PbI2 upon exposure to the electron beam, following a mechanism similar to that of other hybrid lead iodide perovskites (although degradation can be reduced by partially replacing the EA+ ions with Cs+ ions). Interestingly, in some cases during this degradation the formation of an epitaxial interface between (EA x Cs1-x )PbI3 and PbI2 is observed. The photoluminescence emission of the EAPbI3 perovskite nanocrystals, albeit being characterized by a low quantum yield (similar to 1%), can be tuned in the 664-690 nm range by regulating their size during the synthesis. The emission efficiency can be improved upon partial alloying at the A site with Cs+ or formamidinium cations. Furthermore, the morphology of the EAPbI3 nanocrystals can be chosen to be either nanocube or nanoplatelet, depending on the synthesis conditions.Article Citation - Scopus: 2One-step hydrothermal synthesis of spinel manganese oxide ion-sieve from commercial Γ-Mno2 and its uptake performance for lithium(Elsevier Ltd, 2024) Toprak, Seyra; Demir, Mustafa Muammer; Demir, Mustafa Muammer; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe selective extraction of lithium from aqueous systems necessitates efficient sorbent materials. Spinel-type lithium manganese oxide ion sieves (LMOs) have been bee recognized for their high performance in this application. However, the elevated market cost of the spinel form (λ-MnO2) raises economic concerns, posing challenges to the feasibility of the extraction process. In this study, the one-step hydrothermal synthesis of Li1.33Mn1.67O4 was carried out at 200 °C for 7 days using commercial γ-MnO2 powder and aqueous LiOH solution as reactants. The synthesized powder exhibited characteristic XRD reflections consistent with spinel Li1.33Mn1.67O4. Lithium ion-sieve (H1.33Mn1.67O4) was obtained by leaching the LMO product with dilute hydrochloric acid solution. The sorption capacity of γ-MnO2 is increased from 8.4 to 23.1 mg/g (C0=200 mg/L), this capacity is very close to the one of the commercial λ-MnO2. The synthesized spinel HMO sorbent achieved a maximum Langmuir adsorption capacity of 52.1 mg/g. The extraction efficiency reached 94% at the sorbent dose of 20 g/L. The distribution coefficients of metal ions were in the order Li+ > Ca2+ > K+ > Na+, emphasizing selective Li+ extraction from brines with high Na+ content. These findings highlight the successful development of a spinel-type lithium manganese oxide ion sieve from γ-MnO2 polymorph, which is nearly an order of magnitude cheaper than the selective λ-MnO2. The study addresses critical issue of economic feasibility in lithium extraction processes, providing a potential solution for the selective recovery of bulk lithium. © 2024 Elsevier LtdArticle Audio-magnetotelluric (amt) studies over rajapur hot spring in west coast maharashtra, India(indian Acad Sciences, 2024) Deshmukh, Vasu; Chandrasekaram, D.; Kumar, P. V. Vijaya; Chandrasekaram, D.; Raju, Khasi; Sathishkumar, S.; Srinivas, Y.; Rao, P. B. V. Subba; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIn the west coast geothermal provinces, the Rajapur hot spring, located in the southern part of western Maharashtra, is well thought to originate from the interaction of meteoric water with the granitic basement. A 3D AMT survey was conducted to determine the geo-electrical structure of the hot spring. Dimensionality analysis carried out by phase tensor analysis reveals complex subsurface 3D structures. 2D and 3D modelling have yielded three distinct resistivity layers in the Rajapur geothermal field. These layers include a moderately resistive surface layer representing weathered Deccan traps having a thickness of about 100 m, a conductive second layer with a thickness of about 100-400 m represents Kaladgi sediments and a deeper high resistive layer (0.5-1.0 km) representing granitic gneisses basement. High conductivity anomaly within the Kaladgi sediments represents a hydrothermal reservoir that is associated with faults/fractures beneath the Deccan Traps.Article Citation - WoS: 1Citation - Scopus: 1Bioavailability Assessment of the Novel Gsh-Functionalized Feb Nanoparticles Via Oxidative Stress and Trace Element Metabolism in Vitro: Promising Tools for Biomedical Applications(Springer, 2024) Aydemir, Duygu; Çağıran, Özge Balcı; Aribuga, Dilara; Hashemkhani, Mahshid; Acar, Havva Yagci; Çağıran, Özge Balcı; Ulusu, Nuriye Nuray; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIron-based magnetic nanoparticles (NPs) have attracted significant attention in biomedical research, particularly for applications such as cancer detection and therapy, targeted drug delivery, magnetic resonance imaging (MRI), and hyperthermia. This study focuses on the synthesis and glutathione (GSH) functionalization of iron boride (FeB) nanoparticles (NPs) for prospective biomedical use. The GSH-functionalized FeB NPs (FeB@GSH) demonstrated ferromagnetic behavior, with a saturation magnetization (Ms) of 45.8 emu/g and low coercivity (Hc = 1000 Oe), indicating desirable magnetic properties for biomedical applications. Transmission electron microscopy (TEM) analysis of the FeB@GSH revealed well-dispersed nanoparticles with diameters smaller than 30 nm. Comprehensive nanotoxicity and biocompatibility assessments were performed using various healthy and cancer cell lines, including 293 T, HeLa, 3T3, MCF7, HCT116, and CFPAC-1. Cytotoxicity assays were conducted on FeB@GSH-treated cells over a dose range of 0-300 mu g/mL during 24-h incubations. Results indicated no significant differences in cell viability between treated and untreated control groups, confirming the biocompatibility of FeB@GSH. Further nanotoxicity evaluations were carried out on 3T3, 293 T, and CFPAC-1 cell lines, focusing on oxidative stress markers and cellular metabolism by measuring antioxidant enzyme activity. Additionally, ion release and mineral metabolism were assessed using inductively coupled plasma mass spectrometry (ICP-MS), revealing no notable variations between the treated and control groups. These findings suggest that FeB@GSH NPs exhibit excellent biocompatibility, making them promising candidates for diverse biomedical applications, including medical imaging, drug delivery systems, and therapeutic interventions.Book Part Citation - Scopus: 3Advances and Future Perspective of Graphene Field Effect Transistors (gfets) for Medical Diagnostics and Point-Of Tools(World Scientific Publishing, 2022) İnanç, Dilce; Karabacak, Soner; Mutlu, Mustafa Umut; İnanç, Dilce; Karabacak, Soner; Mutlu, Mustafa Umut; Yıldız, Ümit Hakan; Yıldız, Ümit Hakan; 04.04. Department of Photonics; 04.01. Department of Chemistry; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyRecently, major focus has been centered to enhance the capability of graphenebased devices and to facilitate utilization of graphene for biological applications by lowering its toxicity. In this chapter, from synthesis to applications, many of the conspicuous characteristics of graphene have been elaborately reviewed. We primarily focused on graphene-based field effect transistor (FET) for medical diagnostics and point-of-care applications. The device configurations and their application potential as well as sensing capability of various graphene FETs (GFETs) have been discussed. Here, we have also presented several aspects and advantages of GFETs in medical applications while discussing their pros and cons in commercialization. We address the advances and challenges for GFET-based sensing platforms for the medical applications and elaborate the combination strategy of GFETs with the existing commercial systems. © 2023 by World Scientific Publishing Co. Pte. Ltd.Book Part Citation - Scopus: 1A Recycling Route of Plastics Via Electrospinning: From Daily Wastes To Functional Fibers(Walter de Gruyter GmbH, 2019) Isık, Tuğba; Isık, Tuğba; Horzum,N.; Demir, Mustafa Muammer; Demir, Mustafa Muammer; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologySince large-scale plastic production has begun in the 1940s, plastics have been produced and used globally, bringing many advantages to modern life. The consumption of plastics has increased exponentially due to their low cost, chemical resistance, lightness, durability and ability to combine with other materials. However, plastic materials represent high tonnage in urban wastes, and it is known that these plastics discarded at the end of their useful life by filling the landfill sites. Electrospinning is a well-established and versatile technique for the fabrication of submicron fibers. In addition, it is a promising approach for the recycling of waste polymers without using complex methodologies. In this chapter, utilization of electrospinning approach for the recycling of daily wastes will be discussed. The literature about the daily wastes of both synthetic materials and natural/agricultural materials will be analyzed, and the applications of these materials will be given in detail. © 2019 Walter de Gruyter GmbH, Berlin/Boston. All rights reserved.Article Citation - WoS: 3Citation - Scopus: 4A Facile Method for Boosting the Graphitic Carbon Nitride's Photocatalytic Activity Based on 0d/2d S-Scheme Heterojunction Nanocomposite Architecture(Elsevier, 2024) Kahraman, Zeynep; Kartal, Uğur; Kartal, Uğur; Kahraman, Zeynep; Gent, Aziz; Alp, Emre; 03.09. Department of Materials Science and Engineering; 04.04. Department of Photonics; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyGraphitic carbon nitride (g-C 3 N 4 ) has received significant interest as a metal -free photocatalyst. The S -scheme photocatalytic system has great potential to improve the charge separation in semiconductor photocatalysts. In this study, we have fabricated non-toxic and low-cost photocatalytic nanocomposites of 0D/2D S -scheme heterojunction composed of iron oxide and graphitic carbon nitride by a facile method. The developed facile method provides a sustainable way with a high atom economy to further enhance the photocatalytic performance of exfoliated g-C 3 N 4 . The 0D -iron oxide/2D-C 3 N 4 exhibited nearly 10 times better than bulk g-C 3 N 4 and almost 60 % better than exfoliated g-C 3 N 4 under simulated solar light irradiation. The experimental results demonstrated that the effective charge -carrier mechanism led to an improved generation of reactive oxygen species (ROSs), resulting in an impressive photocatalytic performance. A serial photocatalytic test was also conducted to understand photocatalytic reaction mechanisms with various scavengers.Article Electrocaloric Behaviour of Tape Cast and Grain Oriented Nbt-Kbt Ceramics(Elsevier Sci Ltd, 2024) Unal, Muhammet Ali; Karakaya, Merve; Karakaya, Merve; Adem, Umut; Irmak, Tugce; Yildirim-Ozarslan, Gokce; Avci, A. Murat; Fulanovic, Lovro; Adem, Umut; 03.09. Department of Materials Science and Engineering; 01. Izmir Institute of Technology; 03. Faculty of EngineeringWe have investigated the effects of grain orientation and tape casting process on the electrocaloric properties of 0.82Na(0.5)Bi(0.5)TiO(3)-0.18 K0.5Bi0.5TiO3 (0.82NBT-0.18KBT) ceramics at the Morphotropic Phase Boundary (MPB), using direct and indirect measurements. We observe a larger electrocaloric response for the template-free ceramics compared to 7 and 10 wt% template containing ones, suggesting that grain orientation along rhombohedral < 100 > does not improve the electrocaloric response. Indirect measurements yielded a large adiabatic temperature change of around 3 K under an electric field of 50 kV/cm, which is significantly higher than 0.9 K reached at a lower electric field of 40 kV/cm using the direct measurement.Article Citation - WoS: 5Citation - Scopus: 7Impact of Simulated Inflammation and Food Breakdown on the Synergistic Interaction Between Corrosion and Wear on Titanium(Elsevier, 2024) Lima, Ana R.; Toptan, Fatih; Pinto, Ana M.P.; Toptan, Fatih; Alves, Alexandra C.; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThis paper investigates the impact of lactic acid and phosphoric acid additives in artificial saliva (AS), simulating inflammation and food breakdown, on the electrochemical and tribo-electrochemical behavior of titanium. The results showed that, unlike lactic acid, phosphoric acid significantly reduced corrosion resistance, mainly due to local damage and heterogeneities on the passive film. Non-additivated AS caused greater wear volume loss, with mechanical wear identified as the main mechanism. However, when additives were present, a synergistic interplay between corrosion and wear was observed. The study concludes that prolonged exposure to food breakdown could accelerate material degradation in titanium. © 2024 Elsevier LtdArticle Electrocaloric Behaviour of Tape Cast and Grain Oriented Nbt-Kbt Ceramics(Elsevier Sci Ltd, 2024) Unal, Muhammet Ali; Karakaya, Merve; Karakaya, Merve; Adem, Umut; Irmak, Tugce; Yildirim-Ozarslan, Gokce; Avci, A. Murat; Fulanovic, Lovro; Adem, Umut; 03.09. Department of Materials Science and Engineering; 01. Izmir Institute of Technology; 03. Faculty of EngineeringWe have investigated the effects of grain orientation and tape casting process on the electrocaloric properties of 0.82Na(0.5)Bi(0.5)TiO(3)-0.18 K0.5Bi0.5TiO3 (0.82NBT-0.18KBT) ceramics at the Morphotropic Phase Boundary (MPB), using direct and indirect measurements. We observe a larger electrocaloric response for the template-free ceramics compared to 7 and 10 wt% template containing ones, suggesting that grain orientation along rhombohedral < 100 > does not improve the electrocaloric response. Indirect measurements yielded a large adiabatic temperature change of around 3 K under an electric field of 50 kV/cm, which is significantly higher than 0.9 K reached at a lower electric field of 40 kV/cm using the direct measurement.Article Citation - Scopus: 3A Brief Overview on Geothermal Scaling(General Directorate of Mineral Research and Exploration (MTA), 2023) Isık, Tuğba; Demir, Mustafa Muammer; Baba, Alper; Isık, Tuğba; Chandrasekharam, Dornadula; Demir, Mustafa M.; Chandrasekharam, Dornadula; Isık, Tuğba; Baba, Alper; Baba, Alper; Demir, Mustafa Muammer; 03.03. Department of Civil Engineering; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyHot spring waters are rich in terms of minerals. Since there are dramatic changes in thermodynamic parameters in geothermal power plants, such as a decrease in temperature and pressure, severe precipitation occurs throughout the system components in an uncontrolled manner. There are three main chemistries in deposits: carbonates (mainly calcium carbonates), silicates (metal silicates), and sulphides (antimony sulphide-stibnite). Energy harvesting is remarkably reduced out of the insulating nature of the deposit. Various actions need to be taken to mitigate this undesirable issue of scaling in geothermal systems. Geothermal systems are in fact quite complex, and the composition of brine and, accordingly, the chemistry of the deposit are not identical. Therefore, each system should be studied individually, and a tailor-made remedy should be developed. In this overview, the types of deposits in terms of chemistry and the actions (pH modification or antiscalant dosing) that should be taken to reduce scaling are mentioned, and potential chemistries of antiscalants are given.Review Citation - WoS: 5Citation - Scopus: 8A Review on Characterization and Recyclability of Pharmaceutical Blisters(Elsevier, 2023) Capkin, Irem Yaren; Gökelma, Mertol; Gokelma, Mertol; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyPackaging is one of the biggest sectors in the world and the use of aluminium is widespread in the packaging industry. Pharmaceutical blister packages generate a significant amount of solid waste, typically containing plastics and aluminium as thin layers. Since these packages have a complex structure with multiple layers, they are hard to recycle. A separation process of the plastic and aluminium is needed prior to recycling. Hydrometallurgical or thermal processes can be used for the separation. This work reviews the characterization of different types of blisters and the different reagents used in the separation process of the blister layers. Parameters and results of separation processes by using hydrochloric acid, formic acid, acetic acid, organic solvents, and phosphoric acid were discussed as well as the thermal degradation.Article Citation - WoS: 7Citation - Scopus: 10Magnesium-Ion Battery Anode From Polymer-Derived Sioc Nanobeads(Wiley, 2023) Guo, Wuqi; Ahmetoğlu, Çekdar Vakıf; Kober, Delf; Gurlo, Aleksander; Bekheet, Maged F.; İçin, Öykü; Ahmetoğlu, Çekdar Vakıf; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyTin-containing silicon oxycarbide (SiOC/Sn) nanobeads are synthesized with different carbon/tin content and tested as electrodes for magnesium-ion batteries. The synthesized ceramics are characterized by thermogravimetric-mass spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, N2 sorption analysis, scanning electron microscope, energy-dispersive X-ray, and elemental analysis. Galvanostatic cycling tests, rate performance tests, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) tests, and ex situ XRD measurements are conducted. Results of battery performance tests present a high capacity of 198.2 mAh g-1 after the first discharging and a reversible capacity of 144.5 mAh g-1 after 100 cycles at 500 mA g-1. Excellent rate performance efficiency of 85.2% is achieved. Battery performances in this research are influenced by surface area, and tin contentof the SiOC/Sn nanobeads. EIS, CV tests, and ex situ XRD measurements reveal that higher surface area contributes to higher capacity by providing more accessible Mg2+ ion storage sites and higher rate capability by improving the diffusion process. Higher Sn content increases battery capacity through reversible Mg-Mg2Sn-Mg alloying/dealloying process and improves the rate performances by increasing electrical conductivity. Besides, SiOC advances cycling stability by preventing electrode collapse and enhances the capacity due to higher surface capacitive effects. SiOC nanobeads containing Sn nanoparticles are synthesized and tested as anode for magnesium-ion batteries. The anodes show high performance with reversible capacity of 144.5 mAh g-1 after 100 cycles at 500 mA g-1 and excellent rate performance efficiency of 85.2% from 50 to 500 mA g-1.imageArticle Citation - WoS: 3Citation - Scopus: 3Effects of Different Precursors on the Aging and Electrocaloric Properties of Mn-Doped Ba0.95sr0.05tio3 Ceramics(Springer, 2023) Karakaya, Merve; Akdoğan, Yaşar; Erdem, Emre; Karakaya, Merve; Akdoğan, Yaşar; Adem, Umut; Adem, Umut; 03.09. Department of Materials Science and Engineering; 01. Izmir Institute of Technology; 03. Faculty of EngineeringIn this study, the effects of different types of Mn precursors (MnO2 and Mn2O3) and sintering temperature on the defect dipole formation, ferroelectric aging and electrical properties were investigated by using Ba0.95Sr0.05TiO3 ceramics as the base. Both Mn precursors were substituted to the Ti-site as 1 mol% and two different sintering temperatures of 1325 and 1400 degrees C were used to study the effect of grain size. We deduced that slightly higher amounts of Mn2+ can be incorporated into the perovskite structure when MnO2 is used as the precursor, by using X-ray diffraction and electron paramagnetic resonance spectroscopy. Mn-doped samples sintered at 1325 degrees C age faster than those sintered at 1400 degrees C. Aging caused a decrease in the electrocaloric effect whereas Mn-doping increased it. This study shows that Mn precursor used for the acceptor doping affects the amount of Mn incorporated into the structure and therefore electrical properties of the resulting ceramics.Article Citation - WoS: 8Citation - Scopus: 8Design and Performance Comparison of Polymer-Derived Ceramic Ambigels and Aerogels(American Chemical Society, 2023) Soraru, Gian Domenico; Ahmetoğlu, Çekdar Vakıf; İçin, Öykü; Semerci, Tuğçe; Ahmetoğlu, Çekdar Vakıf; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThis work reports the synthesis and characterization of preceramic-and polymer-derived SiOC aerogels obtained from a commercial siloxane resin. The preceramic aerogels were obtained by ambient pressure drying (ambigels) and CO2 supercritical drying. Despite different drying processes, the final ceramic ambi/aerogels have very similar microstructural features in density, porosity, pore size, and specific surface area. Both materials have shown promising results for oil sorption and water cleaning. Supercritically dried-SiOC aerogel had low thermal conductivity with 0.046 W.m(-1).K-1 at RT and 0.073 W.m(-1).K-1 at 500 degrees C. These results suggest that substituting the rather complicated and expensive CO2-SC drying with the more friendly and cheap ambient pressure drying can be done without having to accept significant microstructural/property degradation.Article Citation - WoS: 1Citation - Scopus: 1Effect of Compaction and Fluoride Content on the Remelting Efficiency of Pure Magnesium Chips(Taylor & Francis, 2023) Yörük, Pınar; Gökelma, Mertol; Gökelma, Mertol; Derin, Bora; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyMagnesium is widely used in industries, such as automotive, aerospace, and medical fields. The demand on magnesium has been growing, although the production and melt treatment is complex due to strong oxidation tendency. Recycling of magnesium scraps is crucial due to the criticality of magnesium-containing raw materials in Europe as well as increasing environmental concerns. Remelting of magnesium is typically conducted under a salt flux which absorbs the impurities and protects the melt against oxidation. This study investigates the effect of compaction, fused salt flux, and salt composition on remelting behavior of magnesium chips. Metal yield and coagulation efficiency were calculated after remelting, and samples were characterized by using Scanning Electron Microscope and X-ray Diffraction. The liquidus temperature and density of fluxes were analyzed by FactSage software. Remelting of compacted chips under a fused salt flux with 5 wt.% CaF2 showed the highest magnesium recovery with a yield of 97.7%. Le magnesium est largement utilise dans une variete d'industries, telles que les domaines de l'automobile, de l'aerospatiale et de la medecine. La demande en magnesium s'est accrue, bien que la production et le traitement du bain soient complexes en raison de sa forte tendance a l'oxydation. Le recyclage des dechets de magnesium est crucial en raison de la criticite des matieres premieres contenant du magnesium en Europe ainsi que des preoccupations environnementales croissantes. La refusion du magnesium est effectuee typiquement sous un flux de sel qui absorbe les impuretes et protege le bain contre l'oxydation. Cette etude examine l'effet du compactage, du flux de sel fondu et de la composition du sel sur le comportement a la refusion des copeaux de magnesium. On a calcule le rendement en metal et l'efficacite de la coagulation apres des experiences de refusion, et l'on a caracterise les echantillons a l'aide d'un microscope electronique a balayage et de la diffraction des rayons X. On a analyse la temperature du liquidus (Tliq) et la densite des flux de sel avec le logiciel FactSage. La refusion des copeaux compactes sous un flux de sel fondu avec 5% en poids de CaF2 a montre la recuperation de magnesium la plus elevee avec un rendement de 97.7%Article A Study on Recyclability of Alsi7mg0.3 Machining Waste(2023) Gökelma, Mertol; Gökelma, Mertol; Önen Tüzgel, Rabia; Kaya, Ahmet Yiğit; Özaydın, Onur; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyAluminium products are widely used in the automotive industry. One of the important aluminium products in the automotive is wheel production. Turkish wheel production is expected to reach 360000 tons in 2025. The wheels are produced by Low-Pressure Die Casting at the first stage and the machining process in CNC machines is used to create the final form. A significant amount of machining waste (swarf, turnings, and chips) is created during the machining and the importance of secondary aluminium has been increasing due to environmental and economic concerns. This study focuses on the recycling of AlSi7Mg0.3 cast alloy machining waste. The turnings were sorted into two size fractions and remelted separately under a salt flux in a resistance heating furnace. Two different salt mixtures with different melting points and different salt factors were studied in this work. Metal yield and coagulation yield after remelting were discussed.Article Citation - WoS: 2Citation - Scopus: 4Characterization and Separation Behavior of Multi-Layers in Aluminum-Rich Waste Pharmaceutical Blisters(Springer, 2023) Çapkın, İrem Yaren; Gökelma, Mertol; Gökelma, Mertol; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyAl-rich waste pharmaceutical blisters (WPBs) have a multi-layer structure that contains aluminum and polymer-based fractions. Although the aluminum mass in WPBs is less than typical aluminum packaging products such as beverage cans, establishing a feasible recycling procedure is possible by separating the fractions to recover both metal and plastic. Hydrometallurgical methods are mostly preferred for the separation of aluminum and plastic in multi-layered structures. This work reports the characterization of Al-rich WPBs and the separation behavior of aluminum and plastic layers. The effects of hydrochloric acid, acetic acid, formic acid, sulfuric acid, ethanol, acetone, and organic solvent (benzene–ethanol–water) on the separation behavior of layers were studied at different temperatures. Furthermore, the recycling yield of the aluminum fraction was experimentally assessed. © 2023, The Minerals, Metals & Materials Society.Article Citation - WoS: 5Citation - Scopus: 6Formation of Monolithic Srtio3-Tio2 Ceramic Heterostructures by Reactive Hydrothermal Sintering(Elsevier, 2023) Karacasulu, Levent; Ahmetoğlu, Çekdar Vakıf; Kartal, Uğur; Kartal, Uğur; İçin, Öykü; Karacasulu, Levent; Bortolotti, Mauro; Biesuz, Mattia; Ahmetoğlu, Çekdar Vakıf; 03.09. Department of Materials Science and Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of EngineeringIn a one-pot approach, monolithic SrTiO3-TiO2 ceramic heterostructures were obtained using the reactive hydrothermal liquid phase densification (rHLPD). Structural, morphological, and photocatalytic properties of the obtained ceramics were analyzed. The relative density of the formed components reached about 80% with reaction time, temperature, and NaOH concentration variation. It was observed via Rietveld refinement that there was no XRD detectable phase other than TiO2 and SrTiO3 in the final structure. The monolithic SrTiO3-TiO2 ceramics obtained by hydrothermal reaction at 120 °C for 24 h in 1 M NaOH concentration showed a dielectric constant being around 500, and the dielectric loss was below 0.25 at frequencies higher than 10 kHz. The SrTiO3-TiO2 heterostructured monoliths having only 20 vol% total porosity and low specific surface area, demonstrated ∼60% efficiency (in 5 h) in degrading Methylene Blue photo-catalytically. © 2023 Elsevier LtdArticle Citation - WoS: 8Citation - Scopus: 8Cold Sintering Assisted Two-Step Sintering of Potassium Sodium Niobate (knn) Ceramics(Elsevier, 2023) Karacasulu, Levent; Ahmetoğlu, Çekdar Vakıf; Ahmetoğlu, Çekdar Vakıf; Karacasulu, Levent; 03.09. Department of Materials Science and Engineering; 01.01. Units Affiliated to the Rectorate; 01. Izmir Institute of Technology; 03. Faculty of EngineeringPotassium sodium niobate (KNN) ceramics were densified using a multiple-stage sintering process in which initially applied cold sintering process (CSP) was followed by the solid-state sintering between 1100 and 1120 °C. Comparative assessments demonstrated that multi-step sintered samples yielded better properties than conventionally sintering ones. The highest relative density (94.7%) and the best electrical properties were obtained from the sample subjected to cold sintering at 120 °C/1 h using 5 wt% deionized water subsequently heat-treated at 1120 °C/2 h, resulting in a monolithic KNN ceramic having a piezoelectric coefficient of 120 pC/N. © 2023 Elsevier B.V.
