Browsing by Author "Duran, Hatice"

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Embargo
Continuous conducting architecture developed by supporting Prussian blue analogue on metal-organic framework derived carbon-doped manganese- oxide nanorods for high-performance sodium-ion batteries
(Elsevier BV, 2023-07-03) Ullah, Irfan; Saeed, Roheen; Inayat, Abid; Zubair, Muhammad; Wu, Xianyong; Duran, Hatice; Haider, Ali; Pope, Michael A.; Hussain, Irshad
Prussian blue analogues (PBA) are regarded as promising cathode materials for sodium-ion batteries (SIBs) owing to their open framework with large interstitial sites to accommodate Na+ ions. However, PBA suffer from low electronic conductivity and mechanical instability, which may be improved by their structural modification leading to enhanced kinetics. In this regard, we report an in-situ integration of ultra-small PBA cubes into three-dimensional metal organic framework (MOF) derived carbon-doped manganese oxide nanorods (C-Mn2O3), which form a continuous conductive architecture with intimate PBA/C-Mn2O3 contact. The C-Mn2O3 nanorods provide nucleation sites for the growth of PBA cubes and further act as the electronic pathway to improve electrode reaction kinetics. This hierarchical configuration effectively buffers the lattice expansion, which improve the structural stability of NiCoPBA. Consequently, the composite exhibits promising performance in aqueous Na+ batteries. Specifically, it delivers a high capacity of 97 mAh/g within a narrow potential window of and retained 82% capacity for 1000 cycles in aqueous electrolyte. It shows even higher capacity of 136 mAh/g and similar capacity retention (76% after 1000 cycles) in non-aqueous electrolytes. The promising performance of developed materials demonstrates the significant impact decreasing the size of PBA cubes has on the capacity by reducing the diffusion pathways and thus facilitating intercalation/deintercalation within the cubes. This study offers new insights of exploiting redox-active substrates to modify and stabilize PBA materials for energy storage applications.
Open Access
Dialoxygenation: a preclinical trial for transforming the artificial kidney into an oxygenator
(Lippincott Williams & Wilkins, 2025-01) Karacanoglu, Dilek; Bedir, Esra; Sarıtaş Nakip, Özlem; Kesici, Selman; Duran, Hatice; Bayrakçı, Benan
Critically ill patients sometimes require tandem application of extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) which is easier and cheaper. We aimed to transform the kidney membrane into a lung membrane by adding hydrogen peroxide (H2O2) to the dialysate as the oxygen source. A solution containing H2O2 and a dialysate fluid mixture was used as the final dialysate. Starting with 100% H2O2 solution and gradually reducing the volume of H2O2, respectively: 50%, 10%, 5%, 4%, 3%, 2%, and 1%. PRISMAFLEX system, Prismaflex M60 set and a bag of packed red blood cells (pRBCs) were the prototype. blood flow rate was about 40 ml/minute and the dialysis rate was about 200 ml/m2/minute/1.73 m2. blood sampling times were; at the beginning (T0), at 15th (T1), 30th (T2), 60th (T3) minutes. Amongst eight attempts H2O2 concentration that increased the partial oxygen pressure (pO2) level significantly in a reasonable period, without any bubbles, was 3%. Methemoglobinemia was not observed in any trial. After the test with 3%, H2O2 in the dialysate fluid decreased progressively without any H2O2 detection at post-membrane blood. Three percent H2O2 solution is sufficient and safe for oxygenation in CRRT systems. With this new oxy-dialysate solution, both pulmonary and renal replacement can be possible via a single membrane in a simpler manner.
Open Access
Electronic and structural modification of three-dimensional porous NiCo@NF as a robust electrocatalyst for CO2 emission-free methanol upgradation to boost hydrogen co-production
(American Chemical Society Publications, 2023-09-08) Arshad, F.; Tahir, A.; Haq, T.; Duran, Hatice; Hussain, I.; Sher, F.
Electrochemical hydrogen evolution reaction (HER) coupled with methanol oxidation reaction (MOR) is an innovative process to attain energy-efficient hydrogen generation with more valuable formate product co-generation. Herein, we present 3D porous bimetallic NiCo nanostructures with oxygen vacancies grown on a nickel foam surface (Ov-NiCo@NF) as efficient electrocatalysts that show integrated highly selective methanol oxidation along with hydrogen evolution. The electronic structure of Ov-NiCo@NF is tuned by surface oxygen vacancies that provide a high active surface area and optimum chemisorption energy for selective methanol upgradation to formate. The metallic porous nanostructures and interconnected dendritic growth of nanoparticles ensure electrolyte penetration, with faster gas release ability, that enhances charge transfer kinetics and suppresses support passivation during MOR and HER. The 3D porous Ov-NiCo@NF exhibits improved methanol conversion activity, requiring 1.30 and 1.42 V (vs RHE) to achieve 50 and 100 mA cm-2 current densities for MOR, respectively. Furthermore, an integrated two electrode setup (Ov-NiCo@NF//Ov-NiCo@NF) requires a cell voltage of 1.41 V to attain 25 mA cm-2 current density for methanol-upgrading-assisted water electrolysis, while a higher cell voltage (1.62 V) is required in the electrolyte without methanol (overall water splitting). © 2023 American Chemical Society.
Open Access
Fabrication of NiCu interconnected porous nanostructures for highly selective methanol oxidation coupled with hydrogen evolution reaction
(Elsevier, 2022-01-15) Arshad, F.; Tahir, A.; Haq, T.; Duran, Hatice; Hussain, I.; Sher, F.
Electrocatalytic water electrolysis is the most promising clean and efficient process for pure and clean generation of hydrogen. However, water oxidation reaction requires a large overpotential owing to its slow kinetics, causing a lower efficiency of hydrogen production and high energy consumption. Herein, we report the bimetallic NiCu interconnected porous nanostructures on copper foil (NiCu@Cu) prepared by hydrogen bubbles templating electrodeposition technique for methanol oxidation reaction (MOR), which replaces the kinetically sluggish water oxidation reaction and enhances the hydrogen production with lower energy input. With their high macroporosity, interconnected growth on copper foil with excellent conductivity and easy flow of electrolyte on electrode interface, and stabilization of active sites due to bimetallic synergistic effects, the NiCu@Cu electrocatalysts exhibit outstanding activities for HER and MOR. The NiCu@Cu requiring just 1.32 V anodic potential vs RHE at 10 mA cm−2 for MOR which is significantly lower than that for water oxidation reaction. Moreover, the electrolyzer using NiCu@Cu/NiCu@Cu for anodic MOR and cathodic H2 production only needs a low input voltage of 1.45 V to deliver a current density of 10 mA cm−2 with impressive durability.
Embargo
Histopathology of chironomids exposed to fly ash and microplastics as a new biomarker of ecotoxicological assessment
(Elsevier BV, 2023-12-10) Stojanović, J.; Savić-Zdravković, D.; Jovanović, B.; Vitorović, J.; Bašić, J.; Stojanović, I.; Žabar Popović, A.; Duran, Hatice; Kračun Kolarević, M.; Milošević, Đ.
Histopathology of chironomids exposed to fly ash and microplastics as a new biomarker of ecotoxicological assessment In the last few decades, industrial pollution has gained extensive attention in terms of its effect on the aquatic environment. This imposes the need to develop sensitive biomarkers for early detection of pollutant toxicity in ecotoxicological assessment. The advantages of histopathological biomarkers are many, including quick reaction to the presence of contaminants, and the small number of individuals needed for efficient analysis. The present study analyzed the negative effect of lignite coal fly ash (LCFA) and microplastic particles (MPs) on Chironomus riparius, a suggested model organism by the Organization for Economic Cooperation and Development (OECD). This study aimed to perform histological analyses of larval tissues and target potential changes in treated groups that could serve as promising histopathological biomarkers of the contaminant's negative effects. Following that, other known sensitive sub-organismal biomarkers were analyzed and paired with the histopathological ones. Histological analysis of larvae showed a significantly decreased length of microvilli in midgut regions II and III in both treatments. Treatments with MPs affected oxidative stress parameters: thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPP), superoxide dismutase (SOD), and hemoglobin levels, while LCFA significantly affected all tested sub-organismal biomarkers (DNA damage, levels of AOPP, SOD, and hemoglobin), except catalase (CAT) and TBARS. When observing histological slides, a significant shortage of brush border length in the posterior parts of the midgut was detected in all treatments. In the case of LCFA, the appearance of intensive vacuolization of digestive cells with inclusions resembling apoptotic bodies, in mentioned regions was also detected. This study demonstrated high sensitivity of brush border length to the MPs and LCFA exposure, complementary to other tested sub-organismal biomarkers. Revealing the great potential of this histopathological biomarker in ecotoxicological studies contributes to the international standard ecotoxicology assessment of emerging pollutants.
Open Access
Melting temperature depression and phase transitions of nitrate-based molten salts in nanoconfinement
(American Chemical Society, 2022-07-11) Yazlak, M. G.; Khan, Q. A.; Steinhart, M.; Duran, Hatice
Hybrids of nitrate-based molten salts (KNO3, NaNO3, and Solar Salt) and anodic aluminum oxide (AAO) with various pore sizes (between 25 and 380 nm) were designed for concentrated solar power (CSP) plants to achieve low melting point ([removed]1 W m-1K-1). AAO pore surfaces were passivated with octadecyl phosphonic acid (ODPA), and the results were compared with as-anodized AAO. The change in phase transition temperatures and melting temperatures of salts was investigated as a function of pore diameter. Melting temperatures decreased for all salts inside AAO with different pore sizes while the highest melting temperature decrease (ΔT = 173 ± 2 °C) was observed for KNO3filled in AAO with a pore diameter of 380 nm. Another nanoconfinement effect was observed in the crystal phases of the salts. The ferroelectric phase of KNO3(γ-phase) formed at room temperature for KNO3/AAO hybrids with pore size larger than 35 nm. Thermal conductivity values of molten salt (MS)/AAO hybrids were obtained by thermal property analysis (TPS) at room temperature and above melting temperatures of the salts. The highest increase in thermal conductivity was observed as 73% for KNO3/AAO-35 nm. For NaNO3/AAO-380 nm hybrids, the thermal conductivity coefficient was 1.224 ± 0.019 at room temperature. To determine the capacity and efficiency of MS/AAO hybrids during the heat transfer process, the energy storage density per unit volume (J m-3) was calculated. The highest energy storage capacity was calculated as 2390 MJ m-3for KNO3/AAO with a pore diameter of 400 nm. This value is approximately five times higher than that of bulk salt.
Open Access
The role of intermetallic particles on mode I crack propagation mechanisms in metal plates
(Elsevier Ltd, 2021-08) Tekoğlu, C.; Çelik, Ş.; Duran, Hatice; Bair-Stegmaier, S.; Nielsen, K. L.
In metal plates, the crack propagation mechanism sets the amount of the plastic deformation before failure: a slanted or a cup–cone crack typically yields limited plate thinning within the fracture process zone, while large deformation precedes cup–cup crack propagation. The present work investigates the effect of intermetallic particles on the propagation mechanisms and the associated fracture surface morphologies when tearing Al 1050 plates under far-field mode I loading. Both single edge notched and double edge notched tension specimens, with thicknesses ranging from 0.5 to 5 mm, were tested. The chemical compositions of intermetallic particles were determined by performing energy dispersive X-ray measurements, and their morphological features were characterized by Scanning Electron Microscopy (SEM). Likewise, SEM images were taken to display the fracture surfaces, and the details of the surface morphology were visualized in three dimensions by using X-ray Tomography scanning. The experimental results indicate that an increase in the volume fraction, size, and aspect ratio of the intermetallic particles all promote slanted/cup–cone cracks, while a low amount of small, circular particles leads to cup–cup cracks. Furthermore, two-dimensional finite element simulations for mode I crack propagation support the experimental findings.
Embargo
Silica nanoparticles tailored with a molecularly imprinted copolymer layer as a highly selective biorecognition element
(Wiley-VCH Verlag GmbH & Co. KGaA, 2024-11) Oluz, Zehra; Yazlak, Mustafa Göktürk; Kurşun, Tuğana Talya; Nayab, Sana; Glasser, Gunnar; Yameen, Basit; Duran, Hatice
Molecularly imprinted silica nanoparticles (SP-MIP) are synthesized for the real-time optical detection of low-molecular-weight compounds. Azo-initiator-modified silica beads are functionalized through reversible addition-fragmentation chain transfer (RAFT) polymerization, which leads to efficient control of the grafted layer. The copolymerization of methacrylic acid (MAA) and ethylene glycol dimethacrylate (EDMA) on azo initiator-coated silica particles (≈100 nm) using chain transfer agent (2-phenylprop-2-yl-dithiobenzoate) is carried out in the presence of a target analyte molecule ($_L$-Boc-phenylalanine anilide, $_L$-BFA). The chemical and morphological properties of SP-MIP are characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller surface analysis, and thermogravimetric analysis. Finally, SP-MIP is located on the gold surface to be used as a biorecognition layer on the surface plasmon resonance spectrometer (SPR). The sensitivity, response time, and selectivity of SP-MIP are investigated by three similar analogous molecules ($_L$-Boc-Tryptophan, $_L$-Boc-Tyrosine, and $_L$-Boc-Phenylalanine) and the imprinted particle surface showed excellent relative selectivity toward $_L$-Boc-Phenylalanine ($_L$-BFA) (k = 61), while the sensitivity is recorded as limit of detection = 1.72 × 10⁻⁴ m.
Embargo
The cerium oxide nanoparticles toxicity induced physiological, histological and biochemical alterations in freshwater mussels, Unio crassus
(Elsevier GmbH, 2024-05) Türkmen, Ezgi Uluer; Arslan, Pınar; Erkoç, Figen; Günal, Aysel Çağlan; Duran, Hatice
**Introduction:** Releasing of cerium oxide nanoparticles (nano-CeO₂) to the nature has increased due to the widespread use in many fields ranging from cosmetics to the food industry. Therefore, nano-CeO₂ has been included in the Organization for Economic Co-operation and Development's (OECD) priority list for engineering nanomaterials. In this study, the effects of nano-CeO₂ on the freshwater mussels were investigated to reveal the impact on the freshwater systems on model organism. **Methods:** First, the chemical and structural properties of nano-CeO₂ were characterized in details. Second, the freshwater mussels were exposed to environmentally relevant concentrations of nano-CeO₂ as 10 mg, 25 mg and 50 mg/L during 48-h and 7-d. Third, after the exposure periods, hemolymph and tissue samples were taken to analyse the Total Hemocyte Counts (THCs) histology and oxidative stress parameters (total antioxidant status, glutathione, glutathione-S-transferase, and advanced oxidative protein products). **Results:** Significant decrease of the THCs was observed in the nano-CeO₂ exposed mussels compared to the control group (P < 0.05). The histological results showed a positive association between nano-CeO₂ exposure concentration in the water and level of tissue damage and histopathological alterations were detected in the gill and the digestive gland tissues. Oxidative stress parameters were slightly affected after exposure to nano-CeO₂ (P > 0.05). In conclusion, this study showed that acute exposure of freshwater mussels to nano-CeO₂ did not pose significant biological risk. However, it has been proven that mussels are able to accumulate nano-CeO₂ significantly in their bodies. **Conclusion:** This suggests that nano-CeO₂ may be a potential risk to other organisms in the ecosystem through trophic transfer in the food-web based on their habitat and niche in the ecosystem.
Open Access
Transformation of fly ash-based oxide particles into a functional silica-alumina aerogel and its potential application as an anti-icing surface
(American Chemical Society, 2024-08-07) Bedir, Esra; Citoglu, Senem; Duran, Hatice
Lightweight, surface hydrophobic, highly insulating, and long-lasting aerogels are required for energy conservation and ice-repellent applications. Here, we present the conversion of fly ash to a silica-alumina aerogel (SAA) by utilizing its high silica content. The extracted silica component replaces expensive precursors typically used in conventional aerogel production. Ice adhesion performance was compared to that of polypropylene (PP), an insulating commodity polymer. First, we removed some salt impurities and heavy metals via water and alkaline washing protocols. Then, we produced SAA via the ambient pressure drying method by using trimethylchlorosilane (TMCS) as an adhesion promoter. The newly produced SAA has a surface area of 810 m(2) g(-1) and shows hydrophobic properties with a contact angle of 140 +/- 5 degrees. The thermal conductivity of SAA is 0.0238 W m(-1) K-1 with C-P = 1.1922 MJ m(-3) K-1. The ice adhesion strength of the PP substrate was calculated as 188.30 +/- 51.24 kPa, while the ice adhesion strength of the SAA was measured as 1.21 +/- 0.40 kPa, which was about 150 times lower than that of PP. This indicated that SAA had icephobic properties since ice adhesion strength was less than 10 kPa. This study demonstrates that fly ash-based SAA can be utilized as an economical material with a large surface area and exceptional thermal insulation capacity and is free of harmful compounds (heavy metals), making it potentially suitable as an anti-ice thermal insulation material.
Open Access
Ultraviolet-printing-assisted surface-confined growth of silver nanoparticles on flexible polymer films for Cu2+ and H2S sensing
(American Chemical Society, 2021-08-27) Ashfaq, B.; Azeem, I.; Sohail, M.; Yüce, F. G.; Çitoǧlu, S.; Nayab, S.; Abdullah, M.; Duran, Hatice; Yameen, B.
Metal nanoparticles (NPs) confined on the surface of flexible polymers films are highly sought after for a diverse range of applications. Herein, we report a facile substrate-independent strategy for surface-confined growth of silver NPs (AgNPs) on the surfaces of chemically diverse flexible polymer film substrates represented by polypropylene (PP), polyvinyl chloride (PVC), and polyethylene terephthalate (PET). The surfaces of polymer films were subjected to ultraviolet-printing and conjugated to the hyperbranched polyethyleneimine (PEI). The PEI-functionalized surfaces were subjected to surface-confined growth of AgNPs via three approaches. Besides PEI, the ability of quaternary amine and carboxylic acid functional groups to assist surface-confined growth of AgNPs is also evaluated. All the films with surface-confined AgNPs exhibited absorbance due to the surface plasmon resonance (SPR) characteristic of AgNPs. The AgNPs confined on the surface of PP films were functionalized with 4-mercaptobenzoic acid, and the λmax for SPR absorbance of the resulting platform was found to exhibit a markedly higher bathochromic shift when exposed to Cu2+ ions. This Cu2+ ions sensor could sense Cu2+ ions with a limit of detection of 2.6 ppm. Besides Cu2+ sensing via a bathochromic shift in λmax for SPR absorbance, the SPR absorbance of AgNPs confined on the surface of PP films was found to diminish upon exposure to the aqueous solution of sodium hydrosulfide (NaSH), which acts as a hydrogen sulfide (H2S) donor. The intensity of the SPR absorbance was found to decrease >40% upon exposure to 5 μM aqueous NaSH solution, whereas the SPR signal almost completely disappeared with visual decoloration when the films were exposed to 50 μM aqueous NaSH solution. This highlights the H2S sensing ability of the AgNPs confined on the surface of PP films. In brief, this study is a step toward the future development of flexible chemical sensor platforms and beyond.