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Öğe A magnetically recyclable yolk-shell Au nanocatalyst for catalytic reduction of nitroaromatics and investigation of cytotoxicity on healthy and cancerous cell lines(Elsevier, 2025) Ulusal, Hasan; Ulusal, FatmaThis study aimed to extract gold from waste water produced during secondary gold extraction and create a yolkshell catalyst with a magnetic nanoparticle core. Cytotoxicity tests were performed on healthy and cancerous cells to evaluate the potential of these gold nanoparticles, made from waste gold, in drug delivery. TEM and SEM results showed that the gold nanoparticles were uniformly dispersed in the silica shell of the catalyst without agglomeration. Cytotoxicity tests on healthy human bronchial epithelial cells (BEAS-2B) and cancer cells (SHSY5Y and A549) were conducted to assess the viability and potential use of these nanoparticles in medical drug delivery. Nanoparticles were used at concentrations ranging from 1 to 1000 mu g/mL, and the effects were studied at both 24 and 48 hour exposures. It was found that nanoparticles were nontoxic at low concentrations (<50 g/ mL) but their toxicity increased depending on time and concentration. It has been observed that the cytotoxic effect is less, especially in healthy cells. It was also found that nanoparticles from wastewater were less toxic. Moreover, cytotoxicity studies revealed a direct correlation between the increasing concentration of magnetic gold nanoparticles (MNP-3APP-Au from pure gold, MNP-3APW-Au from waste gold) and their cytotoxic effects. In addition, catalytic reduction of the environmentally toxic 4-nitrophenol, one of the application areas of gold, in the presence of sodium boron hydride was also carried out in order to evaluate the other possible applications of waste gold. It can be said that the catalytic activities of MNP-3APP-Au nanoparticles (98.09 % at 90 min.) obtained from pure gold salt are slightly better than MNP-3APW-Au nanoparticles (97.5 % at 35 min). However, although it takes longer to complete the para nitrophenol conversion, it can be said that the activity of MNP3APW-Au nanoparticles is quite high compared to the literature data.Öğe Altın İşleme Atık Suyundan Mezogözenekli SiO2 destekli Altın Nanopartiküllerinin Sentezi(2023) Ulusal, FatmaBu çalışmada, ramat altınının pirometalurjik ve hidrometalurjik teknikle saflaştırılması sonucu en son kalan atık çözeltisindeki kütlece %1 olan altın, polietilen glikol miseli içerisinde hapsedilmesi ile mezogözenekli SiO2 içine ve yüzeyine nanopartikül olarak tutturulmuştur. Bu amaçla polietilen glikolün 35000 (PEG35000) bileşiği ile tetra etil orto silikat kullanılarak Au3+ içeren atık çözeltiden mezogözenekli SiO2 içinde altın nanopartikülleri hazırlanmıştır. Elde edilen son üründe kütlece %0,4 altın içerdiği ICP-OES ve FESEM analizi ile belirlenmiştir. Oluşan nano malzemeler SEM haritalama analizi ile incelendiğinde altın nanopartiküllerinin mezogözenekli SiO2 içerisinde oldukça homojen bir şekilde dağıldığı ve topaklanma olmadığı görülmüştür. TEM görüntülerinden iki tip oluşum olduğu, ilk oluşumda düzenli bir şekilde oluşmuş düz kanallarına karşılık düzgün altıgen ve bu yapının içi ve yüzeylerine tutunmuş altın nanopartikülleri ile küresel şekilde meydana gelen mezogözenekli SiO2’nin içine gömülmüş altın nanopartiküllerinin oluştuğunu göstermektedir. Her iki oluşumda da altın nanopartiküllerinin boyutlarının 10 nm’den küçük olduğu görülmektedir. Bu çalışma, atık suda kalmış altının geri kazanılarak altın nanopartikülleri elde edilmesi için yeni bir ürün olduğunu ortaya koymaktadır.Öğe Attachment of Idarubicin to Glutaraldehyde-coated Magnetic Nanoparticle and Investigation of its Effect in HL-60 Cell Line(2022) Ulusal, Hasan; Ulusal, Fatma; Bozdayi, Mehmet Akif; Güzel, Bilgehan; Taysı, Seyithan; Tarakçıoğlu, MehmetIdarubicin is a chemotherapeutic drug frequently used to treat breast cancer and acute leukemia. This study aimed to immobilize idarubicin on glutaraldehyde (GA)-coated magnetic nanoparticles (MNP-GA) to prepare a drug with high stability and low toxicity. We prefreed MNPS because of their easy synthesis, low cost, and non-toxicity. In the study, magnetite (Fe3O4) nanoparticles were prepared, coated with glutaraldehyde, characterization processes were performed with Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction pattern (XRD), and Conventional transmission electron microscopy (C-TEM) methods, and idarubicin (IDA) was bound. The cytotoxic effects of idarubicin-bound MNP-GA and free idarubicin on HL-60 cell lines were determined by MTT and ATP tests, and IC50 values were calculated. Flow cytometry was used to evaluate apoptosis status, and the expression of MDR1, Puma, NOXA, BAX, Survivin, and BCL-2 genes were measured by the polymerase chain reaction (PCR). It was found that the IC50 decreased between 5 and 7 times with the use of MNP. In PCR tests, the expressions of apoptotic genes increased, while the expressions of MDR1 and anti-apoptotic genes were decreased in the use of MNP. Apoptosis was found to be increased in flow cytometry measurements. The use of MNP systems has reduced drug resistance since it provides controlled release of the drug and prevents its exit from the cell due to its structure.Öğe Development of mesoporous magnetic nanoparticles supported idarubicin and investigation of apoptotic and cytotoxic effects on cancer cell lines(Springer, 2024) Ulusal, Hasan; Ulusal, Fatma; Ozdemir, NalanBackgroundMany methods are used for cancer treatment, especially chemotherapy. In addition to the their therapeutic effects, chemotherapeutic drugs also have serious disadvantages, such as not being cell and tissue-specific, causing toxicity in many tissues, and developing drug resistance. Many methods, especially nanocarriers, have been designed to overcome these disadvantages.Methods and resultsIn this study, we synthesized mesoporous silica iron oxide nanoparticles with different pore diameters and loaded idarubicin (6MFe3O4-NH2-IDA and 35MFe3O4-NH2-IDA). The synthesized molecules were characterized using FT-IR, XRD, and SEM methods. The cytotoxic effects of unbound idarubicin and idarubicin-loaded nanoparticles on MCF7 and HL-60 cell lines were examined by MTT test. Additionally, the expression of anti-apoptotic (Survivin and BCL-2) and apoptotic (BAX, PUMA, and NOXA) genes of the nanoparticles were measured by PCR method. As a result of the analyses, it was seen that nanoparticles with the desired properties and sizes were synthesized. In MTT analysis, it was observed that both nanoparticles dramatically decreased the IC50 value in cell lines. However, the 35MFe3O4-NH2-IDA molecule was found to have lower IC50 values. IC50 values for pristine IDA, 6MFe3O4-NH2, and 35MFe3O4-NH2 at 24 h were found to be 3.56, 1.24 and 0.25 mu M in the MCF7 cell line and 4.15, 1.16 and 0.34 mu M in the HL-60 cell line, respectively. Additionally, apoptotic gene expression increased, and anti-apoptotic gene expression decreased.ConclusionsOur study demonstrates that the effectiveness of idarubicin can be significantly enhanced by its application with mesoporous nanocarriers. This enhancement is attributed to the controlled release of idarubicin from the nanocarrier, which circumvents drug resistance mechanisms, improves drug solubility, and increases the drug-carrying capacity per unit volume due to the porous structure of the carrier. These findings underscore the potential of the synthesized nanocarrier in cancer treatment and provide a clear direction for future research in this field.Öğe Extraction of malva sylvestris seed oil by soxhlet method and alginate/ chitosan microencapsulation with a new method: Investigation of its cytotoxic effects on human neuroblastoma cell line (SH-SY5Y)(Elsevier, 2024) Ulusal, Hasan; Ulusal, Fatma; Dagli, Sibel; Toprak, CahitBiopolymers such as chitosan or alginate are at the forefront in healthcare applications due to their broad bioactivities. Biomolecules obtained by loading plant extracts into capsules prepared with chitosan and alginate combinations show anticancer, antioxidant and antimicrobial properties. In this study, Malva sylvestris seed oil (MSSO) was extracted by Soxhlet extraction method and alginate/chitosan encapsulation was performed with a new method. The anticancer properties of the prepared capsules were examined in the human neuroblastoma cell line (SH-SY5Y). For this purpose, MSSO was separated by the maceration extraction (Extract 1) and soxhelet extraction (Extract 2) and the extracts were microencapsulated with alginate and chitosan (MicroCapsule 1 and MicroCapsule 2). Encapsulation efficiency (EE%) and drug loading (DL%) were calculated for each two capsules. The cytotoxic effects of the prepared microcapsules and extracts were examined with the CCK-8 cytotoxicity test on the SH-SY5Y cell line for 24 and 48 h of incubation periods. EE and DL for microcapsule 1 were 94.10% and 4.92%, respectively, and EE and DL for microcapsule 2 were 86.69% and 3.15%, respectively. IC50 values calculated using Graphad Prism 10.0.2. As a result of the encapsulation of the extracts, it was found that both capsules had approximately 5 times lower IC50 values. Additionally, lower IC50 values were found at 48 h of incubation due to the slow release of the extracts from the capsules. Since the microencapsulation process increases the amount of substance in the unit volume and provides a slow and controlled release of the drug, it provides cytotoxic effects at lower doses. This will allow the drug to be more concentrated in cancerous cells and tissues and overcome drug resistance that may develop in the cell.Öğe HİGROSKOPİK MADDELERİN ÜRETİMİNDE KULLANILABİLİR SICAKLIK, BASINÇ VE KARIŞTIRMA KONTROLLÜ ULTRASONİK PİLOT REAKTÖR TASARIMI(2023) Köse, Sinan; Ulusal, Fatma; Yetgin, Salih HakanÇinko klorür, sodyum hidroksit, magnezyum oksit, kalsiyum oksit gibi maddeler kimyasal yapıları gereği kristalleri içerisine difüzyon/absorpsiyon gibi yollarla su tutarlar. Bu maddeler, higroskopik maddeler olarak adlandırılıp sıvı ve katılar maddelerden su uzaklaştırmak amacıyla kullanılmaktadır. Üretimleri amacıyla özel kapalı sistemler kullanılması gerekmekle birlikte ortama giren veya maddenin absorpladığı suyun ortamdan uzaklaştırılması ve kalsinasyon işlemleri için yüksek sıcaklıklarda tepkime odaları gerekmektedir. Higroskopik maddelerin tepkimesi sırasında ortaya çıkan gazların ortamdan uzaklaştırılması veya ürünün nemlenmesi önlemek için su buharının sistemden uzaklaştırılması gerekmektedir. Piyasada yer alan reaktörler incelendiğinde başta topaklanma, hantal yapıları, yüksek enerji gereksinimleri ve paketlenme süreçlerinde havayla temas gibi olumsuzluklar göstermektedirler. Bu çalışma ile kalsiyum oksit ve magnezyum oksit temel alınmak üzere, ilgili kimyasalların üretim prosesinde ve kimyasal tepkimelerinde kullanılmak amacıyla yeni bir pilot reaktör ünitesinin sınır şartlarının belirlenmesi ve 3B tasarımlarının yapılması amaçlanmıştır. Piyasada yaygın kullanımı olan reaktörler incelenerek sınır şartları belirlenmiştir. Belirlenen ihtiyaçlara göre 3 boyutlu tasarımları gerçekleştirilmiştir olup elde edilen verilere göre mevcut sistemlere göre %42 daha hafif, %50 daha küçük yeni bir sistem tasarlanmıştır. Çalışma ile en az %38 daha fazla ürün işleme kapasitesine sahip olup %25 oranında enerji kullanımını azaltan bileşenlerden oluşan yeni bir reaktörün tasarımı gerçekleşmiştir.Öğe Horseradish Peroxidase Immobilized onto Mesoporous Magnetic Hybrid Nanoflowers for Enzymatic Decolorization of Textile Dyes: A Highly Robust Bioreactor and Boosted Enzyme Stability(Amer Chemical Soc, 2024) Bakar, Busra; Akbulut, Mustafa; Ulusal, Fatma; Ulu, Ahmet; Ozdemir, Nalan; Ates, BurhanRecently, hybrid nanoflowers (hNFs), which are accepted as popular carrier supports in the development of enzyme immobilization strategies, have attracted much attention. In this study, the horseradish peroxidase (HRP) was immobilized to mesoporous magnetic Fe3O4-NH2 by forming Schiff base compounds and the HRP@Fe3O4-NH2/hNFs were then synthesized. Under optimal conditions, 95.0% of the available HRP was immobilized on the Fe3O4-NH2/hNFs. Structural morphology and characterization of synthesized HRP@Fe3O4-NH2/hNFs were investigated. The results demonstrated that the average size of HRP@Fe3O4-NH2/hNFs was determined to be around 220 nm. The zeta-potential and magnetic saturation values of HRP@Fe3O4-NH2/hNFs were -33.58 mV and similar to 30 emu/g, respectively. Additionally, the optimum pH, optimum temperature, thermal stability, kinetic parameters, reusability, and storage stability were examined. It was observed that the optimum pH value shifted from 5.0 to pH 8.0 after immobilization, while the optimum temperature shifted from 30 to 80 degrees C. K-m values were calculated to be 15.5502 and 7.6707 mM for free HRP and the HRP@Fe3O4-NH2/hNFs, respectively, and V-max values were calculated to be 0.0701 and 0.0038 mM min(-1). The low K-m value observed after immobilization indicated that the affinity of HRP for its substrate increased. The HRP@Fe3O4-NH2/hNFs showed higher thermal stability than free HRP, and its residual activity after six usage cycles was approximately 45%. While free HRP lost all of its activity within 120 min at 65 degrees C, the HRP@Fe3O4-NH2/hNFs retained almost all of its activity during the 6 h incubation period at 80 degrees C. Most importantly, the HRP@Fe3O4-NH2/hNFs demonstrated good potential efficiency for the biodegradation of methyl orange, phenol red, and methylene blue dyes. The HRP@Fe3O4-NH2/hNFs were used for a total of 8 cycles to degrade methyl orange, phenol red, and methylene blue, and degradation of around 81, 96, and 56% was obtained in 8 h, respectively. Overall, we believe that the HRP@Fe3O4-NH2/hNFs reported in this work can be potentially used in various industrial and environmental applications, particularly for the biodegradation of recalcitrant compounds, such as textile dyes.Öğe İlaç Taşımaya Yönelik Yeni Mezogözenekli Fe3O4 Nanotüplerin Sentezi ve Karakterizasyonu(2023) Ulusal, Fatma; Özdemir, NalanManyetik nanopartiküller birçok kullanım alanına sahip olup manyetik olarak saflaştırılabilirlik, geniş yüzey alanı, manyetik hedefleme, yüzey modifikasyonunda kolaylık gibi avantajları sayesinde son yıllarda ilgi çeken malzemelerden biri olmuştur. Gözenekli malzemeler ise, daha fazla açığa çıkan katalitik bölgelere ve geliştirilmiş yüzey işlevselliğine sahip bir malzemeye eldesine imkan sağlar. Ayrıca mezogözenekli Fe3O4 nanotüpleri sahip olduğu eşsiz yapısı sayesinde, bağlanacak ilaç hem destek malzemesinin dış yüzeyine hem de mezogözeneklerine girerek paketlenmiş yapıya benzer bir şekilde bağlanacaktır. Bu sayede hem ilacın yarılanma ömrünü uzatacak hem de parçalanma ürünlerinin hızlı serbestleşmesini engelleyeceğinden ilacın kontrollü bir şekilde taşınabilmesi için ideal bir sistem oluşturacaktır. Bu makalede ilaç hedeflemede kullanılmak üzere mezogözenekli Fe3O4 nanotüp sentezi yapılmıştır. Bu amaçla öncelikle mezogözenekli SiO2 üretimi yapılarak Fe3O4 üretiminde şablon olarak kullanılmıştır. Üretilen mezogözenekli SiO2 yüzeyine, [Fe(NH2CONH2)6](NO3)3 kompleksi kullanılarak Fe3O4 indirgenmiş ve ardından yapıdaki SiO2 liç edilerek mezogözenekli Fe3O4 nanotüp hazırlanmıştır. Hazırlanan malzemeler FESEM, FT-IR, BET, XRD ve TG yöntemleri ile analiz edilmiştir.Öğe Impact of conjugation of whey protein concentrate with different carbohydrates: Monitoring structural and technofunctional variations(Elsevier, 2024) Dıblan, Sevgin; Salum, Pelin; Ulusal, Fatma; Erbay, ZaferThis study utilized whey protein concentrate (WPC) as the primary protein source, employing the Maillard reaction to link it with three distinct carbohydrates: lactose, maltodextrin, and gum Arabic. Mixtures were prepared with a 1:4 protein-to-carbohydrate ratio, and conjugation was performed using dry heating at a temperature of 60 degrees C, 50% relative humidity for 8 h processing time. Under the same conditions, native WPC was heated as a control group. The formation of conjugates was tracked by monitoring absorbance changes, browning index (BI), and reduction in free amino groups (FAG). All conjugates exhibited significant loss of FAG, correlating with an increase in BI. Shifts in protein fingerprint bands observed via Fourier Transform Infrared Spectroscopy suggested potential protein-carbohydrate interactions, while X-ray diffraction showed increased sample crystallinity post-conjugation. Solubility assessments across pH levels (3.0-8.0) indicated a 10-13% rise in solubility for conjugated samples compared to mixtures, broadening their potential applications. Moreover, the emulsion stability index demonstrated improved stability after conjugation. Overall, the Maillard reaction-mediated conjugation enhanced the solubility and stability of emulsions.Öğe Imparting of Nearly Superparamagnetic Properties to Cryogel Scaffolds With Mesoporous MNPs for Magneto-Sensitive Tissue Engineering Strategies(Wiley, 2024) Demir, Didem; Ulusal, Fatma; Ulusal, Hasan; Ceylan, Seda; Dagli, Sibel; Ozdemir, Nalan; Tarakcioglu, MehmetThis work reports the assembly of mesoporous iron oxide nanoparticles (meso-MNPs) with cryogel scaffolds composed of chitosan and gelatin. Meso-MNPs with a particle size ranging from 2 and 50 nm, a surface area of 140.52 m2 g-1, and a pore volume of 0.27 cm3 g-1 were synthesized on a porous SiO2 template in the presence of PEG 6000 followed by leaching of SiO2. Different ratios of meso-MNPs were successfully incorporated into chitosan:gelatin cryogels up to an amount equivalent to the entire amount of polymer. The morphological structure and physicochemical properties of the cryogels were directly affected by the amount of MNPs. VSM curves showed that all composite cryogels could be magnetized by applying a magnetic field. In the context of the safety of magnetic cryogel scaffolds for use in biomedicine, it is important to note that all values are below the exposure limit for static magnetic fields, and according to cytotoxicity data, scaffolds containing meso-MNPs showed nontoxicity with cell viability ranging from 150% to 275%. In addition, microbial analysis with gram-negative and gram-positive bacteria showed that the scaffolds exhibited activity against these bacteria. imageÖğe Investigation of in vitro toxicity of newly synthesized mesoporous silica nanotubes with different pore sizes in human liver cancer cells (HepG2)(İbrahim DEMİRTAŞ, 2024) Ulusal, Hasan; Ulusal, FatmaNanotechnology has gained importance in recent years with the use of nanomaterials smaller than human cells in many areas such as food, cosmetics, defense industry and pharmaceutical industry. It has begun to be widely used in the field of health in the diagnosis and treatment of many diseases, especially cancer. However, due to their size and content, these materials can be toxic and pose a risk to human health. In this study, the cytotoxic effects of mesoporous silicon dioxide (SiO2) nanoparticles with different pore sizes, synthesized using a new method and made from polyethylene glycol 6000 (PEG6000) and polyethylene glycol 35000 (PEG35000) were tested on HepG2 cells liver carcinoma cells. Additionally, the effects of mesoporous silica nanotubes on lipid peroxidation and reactive oxygen species (ROS) were also examined. It was found that the cytotoxicity of both types of mesoporous SiO2 nanoparticles increased with rising concentration. Cell viability decreased significantly as the nanoparticles dosage (100-10 µg/mL) increased. Both nanoparticles were not cytotoxic at concentrations up to 50 µg/mL, however, they became cytotoxic at higher concentrations (pÖğe Investigation of the properties of mesoporous-SiO2 filled EPDM (ethylene propylene diene monomer) rubber(Elsevier, 2025) Bingol, Mehmet Can; Yetgin, Salih Hakan; Kopru, Lker lker; Ulusal, FatmaThis research examined how the addition of mesoporous silicon dioxide (MSiO2) filler affects the rheological, thermal, electrical, and mechanical characteristics of Ethylene-Propylene-Diene-Monomer (EPDM) rubber. In this study, three distinct samples were prepared, each with varying filler loadings: EPDM/5MSiO2 (5 phr), EPDM/11MSiO2 (11 phr), and EPDM/22MSiO2 (22 phr). The mechanical characteristics of these samples were examined, including tensile and tear strength, elongation at break and compression set. Results indicate that minimum torque, the scorch time, cure time, elongation at break %, compression set, abrasion resistance, and UL94-HB-Burning rate were increased while maximum torque, cure extent (CE), cure rate index (CRI), tensile strength, tear strength and current (mA) were decreased with increasing MSiO2 loading. The optimum rubber compound formulation was found in a sample with EPDM/5MSiO2 nanaocomposites which have superior properties, namely tensile strength 13.5 MPa, elongation at break 497 %, 59.4 hardness shore A, tear strength 33.16 (N/mm), compression set 16.4 %, and rebound resilience 64.81 %.Öğe Synthesis of Ag@g-C3N4 coordination compound via Ag(NH2COCN2)6NO3 thermal decomposition and its activities in the catalytic reduction of nitrophenol compounds(Elsevier, 2024) Ulusal, Fatma; Sadi, Berivan; Yetgin, Salih Hakan; Kose, SevimThe activities of silver (Ag) complexes of graphitic carbon nitride with different metal ratios in the catalytic reduction reaction of 4-nitrophenol to 4-nitroamine were investigated in this study. For this purpose, the compounds of urea: dicyanodiamine in a ratio of 3:7 and the Ag(NH2COCN2)6NO3 complex were reacted together in order to prepare Ag@g-C3N4 by thermal decomposition in a single step. The resulting products were analyzed by X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), Field Emission Scanning Electron Microscope- Energy Dispersive X-ray spectroscopy (SEM-EDS), and High-Resolution Transmission Electron Microscope (HRTEM) and the binding properties of Ag in the structure were determined. AAS analysis was also used to determine the amount of silver. The catalytic activities of Ag@g-C3N4 were evaluated for the reduction of p-nitrophenol (PNP) to p-aminophenol (PAP) in the presence of excessive sodium borohydride (NaBH4) as a reducing agent by monitoring conversion at lambda 400 nm. The prepared Ag@ g-C3N4 nanocatalysts were observed to have very good catalytic activity in the range of 95.1-99.6 % in the catalytic reduction reaction in which PNP was used as a model and the catalyst: substrate ratio was studied at 1:5, 1:50 and 1:100. Especially with the leaching problem and the high activity of silver atoms directly added to the g-C3N4 structure with the new synthesis technique, a new material has been added to the literature.Öğe Synthesis of mesoporous magnetic Fe3O4 nanoparticles with different pore sizes and investigation of dye adsorption capacities(Taylor & Francis Inc, 2024) Ulusal, Fatma; Bilici, Zeynep; Ozay, Yasin; Ozdemir, Nalan; Dizge, NadirThis study synthesized mesoporous magnetic Fe3O4 nanoparticles with two pore sizes. First, two different pore sizes of SiO2 were synthesized using polyethylene glycol with molecular weights of 6000 kDa and 35,000 kDa. Next, mesoporous SiO2 was used as a template, and Fe3O4 was coated with a precursor. Then, the silica present in mesoporous SiO2 was leached. The adsorption capacities of the prepared mesoporous magnetic Fe3O4-NPs were compared using an azo cationic dye, Basic Red 18. Parameters such as solution pH, adsorbent amount, and dye concentration were optimized in the adsorption experiments. Additionally, the reusability of Fe3O4-NPs was investigated. The optimum conditions for P6-Fe3O4-NPs were the original pH, 0.5 g/L dose, 50 ppm dye concentration, 60 min contact time, and 100% removal efficiency. For P35-Fe3O4-NPs, the optimal conditions were original pH, 0.75 g/L dose, 20 ppm dye concentration, and 60 min of contact time, with 100% removal efficiency. The second-order kinetic model and Langmuir isotherm were found to be suitable for describing the adsorption of both nanoparticles. Under the optimum conditions, complete dye removal efficiency was achieved for both nanomaterials. Furthermore, in the real wastewater, the adsorption experiment utilizing P6-Fe3O4-NPs yielded a 98% efficiency in color removal at 620 nm.Öğe The effect of modified waste fish bone on mechanical and tribological properties of epoxy composites(Elsevier, 2025) Kose, Sinan; Ulusal, Fatma; Yetgin, Salih HakanA significant amount of fish waste is generated every day worldwide and discharged in large quantities in markets, causing environmental and hygiene problems. Therefore, this study aimed to produce environmentally friendly composite materials with improved mechanical and tribological properties in which waste is utilized. For this purpose, this work investigated the production, characterization, mechanical and tribological performance of surface-modified and unmodified waste fish bone (originated from Rainbow trout) powder-reinforced epoxy composites. Interfacial interaction between the waste fish bone powder and epoxy was investigated by Fourier-transform infrared spectroscopy (FT-IR) and Scanning electron Microscopy (SEM). It was found that the contents of fish bone powder obtained from fish filleting waste affect the mechanical properties and tribological behaviour of epoxy composites. The tensile and flexural strengths of the composites containing fish bone powder improved by 20.6 % and 47.0 %, respectively, compared to the unfilled epoxy as an effect of the thermal treatment. In addition, the coefficient of friction experienced a decrease of 45.8 %, while wear resistance was improved by 34.6 %.Öğe Utilization of supercritical carbon dioxide as green solvent for the Suzuki-Miyaura reaction(Elsevier Science Sa, 2023) Ulusal, Fatma; Erunal, Ebru; Guzel, BilgehanNewly designed alkylated acetyl acetone ligands which are 3-n-butyl-2,4-pentanedione and 3-perfluorobutyl-2,4pentanedione were prepared by alkylation of active methylene group of 2,4-pentanedione and then used as ligands for preparation of palladium (II) (Pd) complexes soluble in supercritical carbon dioxide deposition. The solubility of prepared palladium complexes was inclusively measured in supercritical carbon dioxide at varying pressures and temperatures. The results showed that solubility of the fluorinated complex is higher than the nonfluorinated complex. The solubility of Pd complex of 3-perfluorobutyl-2,4-pentandione [Pd(FBACAC)2] ranged between 4.51 g & BULL;L-1 and 8.66 g & BULL;L-1 while the solubility of Pd complex of 3-n-butyl-2,4-pentandione Pd(BACAC)2 varied from 0.21 g & BULL;L-1 to 1.1 g & BULL;L-1 at different temperature and pressures. Efficient Suzuki-Miyaura crosscoupling reaction catalytic system for novel catalysts was carried out at various temperatures and pressures. To the best of our knowledge, it is the first study without using co-solvent, ionic liquid and phase transfer catalyst for Suzuki-Miyaura C-C coupling reaction in supercritical carbon dioxide catalyst system. The results demonstrated a successful application of novel alkylated acetylacetone for palladium-catalyzed Suzuki-Miyaura coupling reaction between a phenylboronic acid and bromobenzene in scCO2.
