Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
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Article Citation - WoS: 4Citation - Scopus: 3Atomic-Scale Insights Into Carbon Dioxide Hydrogenation Over Bimetallic Iron-Cobalt Catalysts: a Density Functional Theory Study(MDPI, 2023) Tuncer, Dilan; Kızılkaya, Ali CanThe conversion of carbon dioxide to fuels and chemicals is a promising long-term approach for mitigating CO2 emissions. Despite extensive experimental efforts, a fundamental understanding of the bimetallic catalytic structures that selectively produce the desired products is still lacking. Here, we report on a computational surface science approach into the effect of the Fe doping of Co(111) surfaces in relation to CO2 hydrogenation to C1 products. Our results indicate that Fe doping increases the binding strength of surface species but slightly decreases the overall catalytic activity due to an increase in the rate-limiting step of CO dissociation. FeCo(111) surfaces hinder hydrogenation reactions due to lower H coverages and higher activation energies. These effects are linked to the Lewis basic character of the Fe atoms in FeCo(111), leading to an increased charge on the adsorbates. The main effect of Fe doping is identified as the inhibition of oxygen removal from cobalt surfaces, which can be expected to lead to the formation of oxidic phases on bimetallic FeCo catalysts. Overall, our study provides comprehensive mechanistic insights related to the effect of Fe doping on the catalytic behavior and structural evolution of FeCo bimetallic catalysts, which can contribute to the rational design of bimetallic catalysts.Review Citation - WoS: 30Citation - Scopus: 33Molecular Separation by Using Active and Passive Microfluidic Chip Designs: a Comprehensive Review(Wiley, 2023) Ebrahimi, Aliakbar; Didarian, Reza; Shih, Chih-Hsin; Nasseri, Behzad; Ethan Li, Yi-Chen; Shih, Steven; İçöz, Kutay; Tarım, Ergün Alperay; Akpek, Ali; Çeçen, Berivan; Bal Öztürk, Ayça; Güleç, Kadri; Tarım, Burcu Sırma; Tekin, Hüseyin CumhurSeparation and identification of molecules and biomolecules such as nucleic acids, proteins, and polysaccharides from complex fluids are known to be important due to unmet needs in various applications. Generally, many different separation techniques, including chromatography, electrophoresis, and magnetophoresis, have been developed to identify the target molecules precisely. However, these techniques are expensive and time consuming. “Lab-on-a-chip” systems with low cost per device, quick analysis capabilities, and minimal sample consumption seem to be ideal candidates for separating particles, cells, blood samples, and molecules. From this perspective, different microfluidic-based techniques have been extensively developed in the past two decades to separate samples with different origins. In this review, “lab-on-a-chip” methods by passive, active, and hybrid approaches for the separation of biomolecules developed in the past decade are comprehensively discussed. Due to the wide variety in the field, it will be impossible to cover every facet of the subject. Therefore, this review paper covers passive and active methods generally used for biomolecule separation. Then, an investigation of the combined sophisticated methods is highlighted. The spotlight also will be shined on the elegance of separation successes in recent years, and the remainder of the article explores how these permit the development of novel techniques. © 2023 The Authors. Advanced Materials Interfaces published by Wiley-VCH GmbH.Review Citation - WoS: 39Citation - Scopus: 37Engineered Liposomes in Interventional Theranostics of Solid Tumors(American Chemical Society, 2023) Kommineni, Nagavendra; Chaudhari, Ruchita; Conde, Joao; Cecen, Berivan; Chandra, Pranjal; Prasad, Rajendra; Tamburacı, SedefEngineered liposomal nanoparticles have unique characteristicsas cargo carriers in cancer care and therapeutics. Liposomal theranosticshave shown significant progress in preclinical and clinical cancermodels in the past few years. Liposomal hybrid systems have not onlybeen approved by the FDA but have also reached the market level. Nanosizedliposomes are clinically proven systems for delivering multiple therapeuticas well as imaging agents to the target sites in (i) cancer theranosticsof solid tumors, (ii) image-guided therapeutics, and (iii) combinationtherapeutic applications. The choice of diagnostics and therapeuticscan intervene in the theranostics property of the engineered system.However, integrating imaging and therapeutics probes within lipidself-assembly liposome may compromise their overalltheranostics performance. On the other hand, liposomal systems sufferfrom their fragile nature, site-selective tumor targeting, specificbiodistribution and premature leakage of loaded cargo molecules beforereaching the target site. Various engineering approaches, viz., grafting,conjugation, encapsulations, etc., have been investigated to overcomethe aforementioned issues. It has been studied that surface-engineeredliposomes demonstrate better tumor selectivity and improved therapeuticactivity and retention in cells/or solid tumors. It should be notedthat several other parameters like reproducibility, stability, smoothcirculation, toxicity of vital organs, patient compliance, etc. mustbe addressed before using liposomal theranostics agents in solid tumorsor clinical models. Herein, we have reviewed the importance and challengesof liposomal medicines in targeted cancer theranostics with theirpreclinical and clinical progress and a translational overview.Erratum Citation - WoS: 1Corrigendum: Bioactive Snail Mucus-Slime Extract Loaded Chitosan Scaffolds for Hard Tissue Regeneration: The Effect of Mucoadhesive and Antibacterial Extracts on Physical Characteristics and Bioactivity of Chitosan Matrix (2021biomed. Mater.16 065008)(NLM (Medline), 2023) Perpelek, M.; Tamburaci, S.; Aydemir, S.; Tıhmınlıoğlu, F.; Baykara, B.; Karakaşli, A.; Havitçioǧlu, H.Article Citation - WoS: 17Citation - Scopus: 16Development of Cissus Quadrangularis-Loaded Poss-Reinforced Chitosan-Based Bilayer Sponges for Wound Healing Applications: Drug Release and in Vitro Bioactivity(American Chemical Society, 2023) Değer Aker, Sibel; Tamburacı, Sedef; Tıhmınlıoğlu, FundaNowadays, antibiotic-loaded biomaterials have been widelyusedin wound healing applications. However, the use of natural extractshas come into prominence as an alternative to these antimicrobialagents in the recent period. Among natural sources, Cissus quadrangularis (CQ) herbal extract is usedfor treatment of bone and skin diseases in ayurvedic medicine dueto its antibacterial and anti-inflammatory effects. In this study,chitosan-based bilayer wound dressings were fabricated with electrospinningand freeze-drying techniques. CQ extract-loaded chitosan nanofiberswere coated on chitosan/POSS nanocomposite sponges using an electrospinningmethod. The bilayer sponge is designed to treat exudate wounds whilemimicking the layered structure of skin tissue. Bilayer wound dressingswere investigated with regard to the morphology and physical and mechanicalproperties. In addition, CQ release from bilayer wound dressings and in vitro bioactivity studies were performed to determinethe effect of POSS nanoparticles and CQ extract loading on NIH/3T3and HS2 cells. The morphology of nanofibers was investigated withSEM analysis. Physical characteristics of bilayer wound dressingswere determined with FT-IR analysis, swelling study, open porositydetermination, and mechanical test. The antimicrobial activity ofCQ extract released from bilayer sponges was investigated with a discdiffusion method. Bilayer wound dressings' in vitro bioactivity was examined using cytotoxicity determination, woundhealing assay, proliferation, and the secretion of biomarkers forskin tissue regeneration. The nanofiber layer diameter was obtainedin the range of 77.9-97.4 nm. The water vapor permeabilityof the bilayer dressing was obtained as 4021 to 4609 g/m(2)day, as it is in the ideal range for wound repair. The release ofthe CQ extract over 4 days reached 78-80% cumulative release.The release media were found to be antibacterial against Gram-negativeand Gram-positive bacteria. In vitro studies showedthat both CQ extract and POSS incorporation induced cell proliferationas well as wound healing activity and collagen deposition. As a result,CQ-loaded bilayer CHI-POSS nanocomposites were found as a potentialcandidate for wound healing applications.Article Citation - WoS: 11Fabrication of Helix Aspersa Extract Loaded Gradient Scaffold With an Integrated Architecture for Osteochondral Tissue Regeneration: Morphology, Structure, and in Vitro Bioactivity [2](American Chemical Society, 2023) Tamburacı, Sedef; Perpelek, Merve; Aydemir, Selma; Baykara, Başak; Havıtçıoğlu, Hasan; Tıhmınlıoğlu, FundaRegeneration of osteochondral tissue with its layered complex structure and limited self-repair capacity has come into prominence as an application area for biomaterial design. Thus, literature studies have aimed to design multilayered scaffolds using natural polymers to mimic its unique structure. In this study, fabricated scaffolds are composed of transition layers both chemically and morphologically to mimic the gradient structure of osteochondral tissue. The aim of this study is to produce gradient chitosan (CHI) scaffolds with bioactive snail (Helix aspersa) mucus (M) and slime (S) extract and investigate the structures regarding their physicochemical, mechanical, and morphological characteristics as well as in vitro cytocompatibility and bioactivity. Gradient scaffolds (CHI-M and CHI-S) were fabricated via a layer-by-layer freezing and lyophilization technique. Highly porous and continuous 3D structures were obtained and observed with SEM analysis. In addition, scaffolds were physically characterized with water uptake test, micro-CT, mechanical analysis (compression tests), and XRD analysis. In vitro bioactivity of scaffolds was investigated by co-culturing Saos-2 and SW1353 cells on each compartment of gradient scaffolds. Osteogenic activity of Saos-2 cells on extract loaded gradient scaffolds was investigated in terms of ALP secretion, osteocalcin (OC) production, and biomineralization. Chondrogenic bioactivity of SW1353 cells was investigated regarding COMP and GAG production and observed with Alcian Blue staining. Both mucus and slime incorporation in the chitosan matrix increased the osteogenic differentiation of Saos-2 and SW1353 cells in comparison to the pristine matrix. In addition, histological and immunohistological staining was performed to investigate ECM formation on gradient scaffolds. Both characterization and in vitro bioactivity results indicated that CHI-M and CHI-S scaffolds show potential for osteochondral tissue regeneration, mimicking the structure as well as enhancing physical characteristics and bioactivity. © 2023 The Authors. Published by American Chemical Society.Article Citation - WoS: 4Citation - Scopus: 5Numerical Study of Fluid Flow and Mixing in the Argon Oxygen Decarburization (aod) Process(Iron and Steel Institute of Japan, 2023) Cheng, Zhongfu; Wang, Yannan; Dutta, Abhishek; Blanpain, Bart; Guo, Muxing; Malfliet, AnneliesA three-dimensional (3D) model has been developed based on the Eulerian multiphase flow approach to investigate the fluid flow behavior and mixing efficiency in the multi-tuyere AOD process. The interphase forces, including drag force, lift force, virtual force, turbulent dispersion force, and wall lubrication force, were incorporated into this model. The model was used to simulate six-tuyere and seven-tuyere AOD processes. The phenomena of multi-jet penetration, bubble plume merging, 3D turbulent flow and mixing characteristics were considered. The results indicate that the bubble plume merging occurs in the upper part of the liquid bath, forming a typical plume cluster. The predicted penetration length for a single tuyere jet agrees well with the previous work. For the multi-jet system, the side jets penetrate deeper than the inside ones. The six-tuyere AOD has a good flow condition in the center of the liquid bath, while the seven-tuyere AOD has a better flow pattern in the sidewall region and the lower bath. Overall, the seven-tuyere AOD performs better in mixing efficiency than the six-tuyere AOD under the same gas flow rate. These findings increase the understanding of the AOD process, allowing further optimization of process parameters. This model can be further extended to incorporate the thermochemical reactions into the modeling of the AOD reactor.Article Citation - WoS: 10Citation - Scopus: 12Novel Hybrid Adsorption-Electrodialysis (aded) System for Removal of Boron From Geothermal Brine(American Chemical Society, 2022) Altınbaş, Bekir Fırat; Orak, Ceren; Ökten, Hatice Eser; Yüksel, AslıA novel hybrid adsorption-electrodialysis (AdED) system to remove environmentally harmful boron from geothermal brine was designed and effective operating parameters such as pH, voltage, and flow rate were studied. A cellulose-based adsorbent was synthesized from glycidyl methacrylate (GMA) grafted cellulose and modified with a boron selective n-methyl-d-glucamine (NMDG) group and characterized with SEM-EDX, FT-IR, and TGA analyses. Batch adsorption studies revealed that cellulose-based adsorbent showed a remarkable boron removal capacity (19.29 mg/g), a wide stable operating pH range (2-10), and an adsorption process that followed the Freundlich isotherm (R2= 0.95) and pseudo-second-order kinetics (R2= 0.99). In the hybrid AdED system, the optimum operating parameters for boron removal were found to be a pH of 10, a voltage of 10 V, a flow rate of 100 mL/min, and an adsorbent dosage of 4 g/L. The presence of the adsorbent in the hybrid system increased boron removal from real geothermal brine (containing 199 ppm boron) from 7.2% to 73.3%. The results indicate that the designed AdED system performs better than bare electrodialysis for boron removal from ion-rich real geothermal brine while utilizing environmentally friendly cellulose-based adsorbent.Article Citation - WoS: 11Citation - Scopus: 12Box-Behnken Design for Hydrogen Evolution From Sugar Industry Wastewater Using Solar-Driven Hybrid Catalysts(American Chemical Society, 2022) Orak, Ceren; Yüksel, AslıHydrogen is a clean and green fuel and can be produced from renewable sources via photocatalysis. Solar-driven hybrid catalysts were synthesized and characterized (scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, and UV-vis diffuse reflectance spectroscopy (DSR)), and the results implied that graphene-supported LaRuO3is a more promising photocatalyst to produce hydrogen and was used to produce hydrogen from sugar industry wastewater. To investigate the main and interaction effects of reaction parameters (pH, catalyst amount, and [H2O2]0) on the evolved hydrogen amount, the Box-Behnken experimental design model was used. The highest hydrogen evolution obtained was 6773 μmol/gcatfrom sugar industry wastewater at pH 3, 0.15 g/L GLRO, and 15 mM H2O2. Based on the Pareto chart for the evolved hydrogen amount using GLRO, among the main effects, the only effective parameter was the catalyst amount for the photocatalytic hydrogen evolution from sugar industry wastewater. In addition, the squares of pH and two-way interaction of pH and [H2O2]0were also statistically efficient over the evolved hydrogen amount.Article Citation - WoS: 7Citation - Scopus: 7Cross-Linked Phosphorylated Cellulose as a Potential Sorbent for Lithium Extraction From Water: Dynamic Column Studies and Modeling(American Chemical Society, 2022) Recepoğlu, Yaşar Kemal; Yüksel, AslıPhosphorylated functional cellulose was cross-linked with epichlorohydrin at different ratios because it is a very hydrophilic substance that instantly swells to form a hydrogel when it comes into contact with water. It was aimed to utilize a continuously packed bed column to recover lithium from water under varying operating conditions such as flow rate and bed height. The characterization results confirmed cross-linking based on morphology, structure, surface area, and thermal stability differences. Lithium recovery was more efficient with a low flow rate, but the dynamic sorption process was independent of bed height. The total capacities at the three flow rates with 1.5 cm bed height were 33.56, 30.15, and 25.54 mg g-1, and the total saturation times at the three different bed heights with 0.5 mL min-1 flow rate were 659, 1001, and 1007 min, respectively. Only 15.75 mL of 5% H2SO4 solution was required to desorb approximately 100% of Li from the saturated sorbent.