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    Aluminum Gearbox of Vehicle Engine Recycling
    (Yasin Akın AYTURAN, 2020) Dursun, Şükrü; Ölmez, Hamza; Uysal, M. Enes; Demirbaş, Emre; Aksu, Mecit
    The usage of natural mines and materials is rapidly increasing in parallel to population growth and industrial developments. It is very important for future generations that the materials used are transported to landfills and protected from mineral resources by preventing them from being thrown into the environment. Separation of materials produced from different metals as much as possible, production of new materials, protection of mineral resources, and reduction of environmental pollution is also very important in economic terms. In addition to legal sanctions for the recycling of metals and other resources, voluntary organizations are making efforts in this regard. For the ones with high production and cost value at the beginning of recycled materials, more successful results are obtained. In the aluminium recycling plant, the collection and disassembly of the vehicle engines and vehicle transmissions are used in the domestic and abroad, and the dismantling of the aluminium alloys prepared according to the specifications requested by the customers. It is considered during this project stage that the vehicle engines and vehicle transmissions from domestic and foreign countries will not need to be recycled, and the vehicle engines and vehicle transmissions will be sold directly if they can be used directly in the vehicles after the necessary repairs.
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    Effect of CuO doping on the performance of LaB6 interlayer films in Al/CuO:LaB6/p-Si/Al diodes
    (Elsevier, 2023) Ocaya, Richard O.; Al-Sehemi, Abdullah G.; Tataroglu, Adem; Dere, Aysegul; Erol, Ibrahim; Aksu, Mecit; Al-Ghamdi, Ahmed A.
    This study investigates the fabrication and performance analysis of Al/CuO:LaB6/p-Si/Al diodes with CuO-doped LaB6 interlayer films of varying concentrations (1%, 5%, and 10%). Experimental evidence demonstrates the limitations of 0% CuO doping, as pure LaB6 lacks a significant barrier height, resulting in ohmic behavior unsuitable for intended applications. Through comprehensive analyses under varying illuminations (20-100 mW/cm2) and frequencies (10 kHz-1 MHz), the study reveals that controlling CuO doping in LaB6 significantly enhances the effective barrier height at the LaB6:CuO heterojunction, improving rectification properties. This enhancement enables the diode to be well-suited for high-speed photonic devices utilizing one-step photoemission. The findings contribute to the development of high-performance LaB6-based devices, advancing photonic technologies by emphasizing the advantages of CuO doping.
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    Employing of 2-Acetylpyridine Based Chalcone as Hg2+ Sensing Material: Experimental and Theoretical Examination
    (Düzce Üniversitesi, 2022) Musatat, Ahmad Badreddin; Atahan, Alparslan; Aksu, Mecit; Zengin, Mustafa
    This study reports the evaluation of 2-acetylpyridine based chalcone structure as a useful sensing material for Hg2+ ion detection by the means of UV-visible spectroscopy. In this context, firstly, the most common twenty metal ions were treated by the chalcone structure which was synthesized from 2-acetylpyridine and 4-diphenylaminobenzaldehyde according to the known procedures. As result, the studied chalcone compound exhibited good sensing activity towards Hg2+ ion in acetonitrile/water medium with significant red-shift phenomenon. In addition, some photophysical/electronic parameters of the chalcone and its Hg2+ complex were determined experimentally and theoretically. B3LYP, PBE0 methods and SVP, TVZP, and TVZPP basis sets were used for theoretical calculations in acetonitrile media. Finally, experimental results were explained and the proposed sensing mechanism was supported via density functional theory (DFT) outputs.
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    Experimental Study on The Gamma Ray Absorption Properties of Lanthanum and Cerium Borides
    (2023) Gülbiçim, Hasan; Özcan, Aynur; Türkan, Nureddin; Aksu, Mecit; Kurt, Esra
    The objective of this study is to investigate the mass attenuation coefficients (?m) of lanthanumhexaborides and ceriumhexaborides over a wide photon energy range emitted from the main radioactive sources used in medicine and industry. 125I, 99mTc, 131I, 137Cs, 60Co and 152Eu gamma ray sources were used in the experiments. The materials synthesized in powder form were first pelletized and then irradiated by photon beams. At the end, it was seen that there is successful consistency between the obtained experimental data and the previous theoretical results. It was also observed that the investigated samples are comparable enough to the known standard gamma shielding materials, especially to lead which is one of the most common one. In conclusion, it is understood that the presently investigated samples have a promising aspect in terms of developing new shielding materials against gamma rays.
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    Fabrication of photodiodes based on graphene oxide (GO) doped lanthanum hexaboride (LaB6) nanocomposites
    (Elsevier Science Sa, 2024) Yalcin, Mesut; Al-Sehemi, Abdullah G.; Erol, Ibrahim; Aksu, Mecit; Tillayev, Sanjar; Dere, Aysegul; Al-Ghamdi, Ahmed A.
    GO-doped LaB6 nanocomposite-based Al/p-Si/GO:LaB6/Al photodiodes were fabricated for the study. The electrical properties of the fabricated photodiodes were subjected to current-voltage and capacitance-voltage measurements. The ideality factors, barrier heights and series resistance values of photodiodes were calculated and compared using the Cheung-Cheung and Norde methods approaches. The lowest ideality factor values were calculated to be 4.75, 4.00 and 9.21 in the samples doped with GO at 1 %, 5 % and 10 %, respectively, and the highest barrier height values were calculated from the Norde function to be 0.75, 0.64 and 0.75 eV, respectively Additionally, the responsivity (R) and detectivity (D) values of the diodes were calculated. The R values of 1 %, 3 % and % 5 doped diodes were calculated as 2153, 6001 and 2042 mA/W at, 100 mW/cm(2), respectively. The D* values of 1 %, 3 % and % 5 doped diodes are calculated as 1.38 x 10(11), 3.85 x 10(11) and 1.31 x 10(11) Jones at 100 mW/cm(2), respectively. The interface state (Nss) of 1 %, 3 % and % 5 doped diodes were calculated as 2 x 10(13), 1.25 x 10(13) and 1.06 x 10(13)eV(-1) cm(-2), at 100 mW/cm(2), respectively. It can be concluded that the diodes produced in this study have potential for use in optoelectronic applications.
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    Gamma ray shielding properties of synthesized lanthanide borides using EGSnrc code
    (Elsevier, 2023) Gulbicim, Hasan; Aksu, Mecit; Turkan, Nureddin; Babuz, Cansu
    In this study, we have investigated some hexaborides which are synthesized for the purpose of gamma-ray shielding. These materials were synthesized by the method of magnesiothermic reduction process in the open air, and stoichiometric amounts of M2O3, B2O3, and Mg (20% excess) were mixed where MIII is a three oxidation state lanthanide metal (DyIII, PrIII and YbIII) ion. Chemical and physical characteristics of the manufactured samples were determined by X-ray Diffractometry (XRD), Energy Dispersive X-ray Spectroscopy (EDX) and Scanning Electron Microscopy (SEM) analyzes. Gamma-ray shielding parameters were determined by using EGSnrc Monte Carlo (MC) code in 21.0 keV-1.728 MeV photon energy range. The calculated data were compared with the results calculated by Nist's XCOM database. The obtained results by using EGSnrc and XCOM program have shown successful consistency. It was concluded that the manufactured hexaborides have promising gamma shielding properties compared especially to lead and some shielding materials investigated earlier in the literature.
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    Generation of hydrogen in the hydrolysis of NaBH4 using Ir(0) catalyst
    (Chemical Publishing Co., 2014) Aksu, Mecit
    This study reports the results of kinetic of hydrogen generation from the catalytic hydrolysis of sodium borohydride. Iridium(0) particles catalyst was stabilized by diethylene glycol. Catalyst iridium was characterized by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Hydrolysis of sodium borohydride was carried out both with and without stirring. Effect of stirring, sodium hydroxide concentration and sodium borohydride concentration on hydrogen volume and yield of hydrogen generation was investigated for optimization. It was found that rate of H2 generation decreased with increasing NaOH concentration while increased with increasing concentration of NaBH4. Stirring has positive effect on rate of hydrogen generation. © 2014, Chemical Publishing Co. All rights reserved.
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    Growth of nano (NA)V2O5from nabh4 and v2o5 at room temperature
    (Chemical Publishing Co., 2014) Aksu, Mecit
    In this work V2O5 was reduced to sodium intercalated NaV2O5 with NaBH4 in pyridine-water solvent. Techniques to investigate the composition, crystallinity and morphology of products as prepared include field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray powder diffraction inductively coupled plasma-atomic emission spectroscopy. Unit cell parameters are a = 11.28, b = 3.583, c = 4.76 Å and ? = ?b = ? = 90° . Mean crystallite size was calculated to be 4.8 nm.
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    Korozyona Uğramış Siloların Bakımı: Bir Vaka Çalışması
    (Duzce University, 2025) Gerengi, Hüsnü; Maraşlı, Muhammed; Coskun, Kader; Ozdal, Volkan; Uygur, İlyas; Aksu, Mecit
    Yakıt, gıda ve kimyasalların depolanması için kullanılan silolar, inşaat sektöründe yaygın olarak kullanılan çimento, agrega ve katkı maddeleri gibi çeşitli kimyasalları güvenli bir şekilde depolamak ve dağıtmak için tasarlanmış özel yapılardır. Cam elyaf takviyeli beton (GFRC) panel üretimi için gerekli malzemelerin çoğu silolarda depolanır. Gerekli malzemeler, otomatik dozaj sistemi ile donatılmış pompalar yardımıyla silolardan alınır. Havadaki nem ve oksijene maruz kalan siloların korozyona uğrayıp pas oluşturması yüksek ihtimaldir. Açık havada, özellikle aşırı nem ve yağış alan yerlerde silolar zamanla daha hızlı korozyona uğrar. Dolayısıyla korozyon nedeniyle delinen silolar üretimin durmasına ve ciddi mali kayıplara yol açabilir. Boyama, metal yüzey ile çevre arasında bir bariyer oluşturarak korozif maddelerle doğrudan teması önlediği ve çelik yapının ömrünü uzattığı için çeliği korozyondan korumanın başlıca yöntemlerinden biridir. Bu çalışmada, Fibrobeton GFRC şirketi tarafından 20 yıldır kullanılan ve ağır korozyona uğramış iki silonun bakım çalışmaları ASTM D3276, ISO 8501 ve ISO 12944:2018 standartlarına göre adım adım gerçekleştirilmiştir. Eski boyanın silo yüzeyinden uzaklaştırılması için sulu kumlama kullanılmış, ardından korozyon inhibitörleri içeren patentli bir asit çözeltisi (TPE Patent Başvuru No: 2017/11354) ile oksit tabakası temizlenmiş, ardından iki kat yüzey toleranslı (Zn³(PO4)² bazlı) epoksi boya ve ardından UV dayanımı yüksek akrilik boya uygulanmıştır. Bu çalışmada bakım işlemi sırasında metal yüzeyin boya öncesi standartlara uygun olarak hazırlanmamasından kaynaklanan sorunlara da dikkat çekildi.
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    Magnezyotermik İndirgeme ile PrB6 Sentezi
    (2021) Babuz, Cansu; Aksu, Mecit
    Bu çalışmada, magnezyotermik indirgeme ile mikro ve nano boyutta PrB6 sentezlendi ve optimum reaksiyon koşulları tespit edildi. Optimum sıcaklığı belirlemek için Praseodymium(III, IV) oksit, bor(III) oksit ve magnezyum reaksiyon süresi sabit tutularak (2 saat) 600, 700, 800 ve 900°C‘de tepkime vermeleri sağlandı. Optimum sıcaklık 900°C olarak saptandı. Daha sonra optimum olan sıcaklıkta (900°C) sabit tutularak 4, 8, 12, 16, 20 saat süreyle tepkime vermeleri sağlandı. En uygun tepkime süresi 8 saat olduğu tespit edildi. Oluşan saf PrB6 X-Işını Kırınımı (XRD), Taramalı Elektron Mikroskobu (SEM) ve Enerji Dispersif Spektrometri (EDS) ile analiz edildi. XRD analizi ile saf PrB6 oluştuğu XRD ile kanıtlandı. Numunelerin morfolojilerini karakterize etmek için SEM analizi yapıldı. Heterojen ve nano–mikro boyutta PrB6 varlığı gözlendi.
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    Monte Carlo simulation of gamma shielding properties of Lanthanum hexaboride (LaB6) and Cerium hexaboride (CeB6) materials synthesized by magnesiothermic reduction
    (Gazi Univ, Fac Engineering Architecture, 2023) Özcan, Aynur; Türkan, Nureddin; Aksu, Mecit; Gülbiçim, Hasan; Kurt, Esra
    Purpose: The purpose of this study is to synthesize the lanthanum hexaboride and cerium hexaboride materials within the optimum durability conditions and also investigate their gamma ray absorption features by using Monte Carlo method.Theory and Methods: Magnesiothermic reduction techniqe was used to synthesize materials by convenient experimental set up. Molecular structure and contents of the materials were determined using XRD and EDX spectroscopy for using the results in the Monte Carlo simulations. Beer-Lambert law was applied to calculate transmitted, absorbed and reflected quantity of incident photons directed onto material longitudinally. Atomic cross-section data of the related media were calculated by PEGS4 code of EGSnrc with broad photon energy range including low and high energy regions. After that, radiation absorption parameters such as mu/rho, HVL, TVL and MFP were calculated by using the developed code. Similar calculations were carried out by XCOM program to compare consistency of the obtained results. The calculated results were also compared with the previously investigated results for vermiculite, concrete, borosilicate, granite and lead.Results: The authors were succeeded desired purity level of the synthesized materials within the optimum conditions experimentally. It was observed from the calculated results that the lanthanum and the cerium hexaborides have higher absorption capability of gamma rays according to the aforementioned materials. It was also observed that they were more comparable with lead which is the standard shielding material.Conclusion: The results obtained from this study have showed that the synthesized materials are more promising than some previously investigated materials for radiation shielding. By thinking in terms of advantages and disadvantages, these materials may play an important role for protection of the people from hazardous effects of radiations used in medicine, industry, agriculture, nuclear power plants, research reactors, etc.
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    Nano and microsized EuB6 via magnesiothermic reduction
    (Korean Assoc Crystal Growth, Inc, 2013) Aksu, Mecit; Aydın, Esra
    In this study, nano and micro sized EuB6 was synthesized via magnesiothermic reduction in open air. Method is optimized according to temperature and reaction time. Optimum temperature and reaction time are determined to be 600. C and 4 hours. Products were analysed with x-ray diffraction (XRD), Scanning electron microscopy (SEM). XRD analysis proved formation of pure EuB6 and SEM analysis were used to characterize structure and morphologies of samples. Nanosized and microsized EuB6 with heterogeneous morpholgy was observed.
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    New Energetic Copper(II) Complexes With Pyrazolyl Type Ligands
    (Wiley-V C H Verlag Gmbh, 2011) Öz, Sevi; Svoboda, Ingrid; Kurtaran, Raif; Aksu, Mecit; Sarı, Musa; Kunduracı, Melike; Atakol, Orhan
    Nine Cu-II complexes (I-IX) containing the azide ion and bis-2,6-(pyrazol-1-yl)pyridine (pp), bis-2,6-(pyrazol-1-yl)pyridine (dmpp), and 2-(pyrazol-1-yl)-6-(3,5-dirnethylpyrazol-1-yl)pyridine (mpp), which are derivatives of pyrazolylpyridine, were prepared in nonaqueous medium. These complexes were characterized by elemental analyses and IR spectroscopy. Crystals of one of these complexes [CumppClN(3) (VII)] were prepared in suitable size, and a molecular structure of this complex was obtained with X-ray diffraction method. Complexes were examined by thermogravimetry and differential scanning calorimetry methods. Thermal decomposition was observed in complexes including two azide groups similar to that seen in explosives. In the complexes containing one azide group, formation of the Cu-1 complexes was observed after thermal decomposition of the azide group.
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    Novel bionanocomposites of chitosan-based blend containing LaB6: Thermal, dielectric, and biological properties
    (Wiley, 2023) Erol, Ibrahim; Hazman, Omer; Aksu, Mecit; Uygur, Ilyas
    In the presented study, a strategy that will offer alternative usage areas by strengthening the physicochemical properties of the green polymer chitosan (CS) is aimed. For this purpose, a compatible blend of CS (CS-PFPAMA) with poly 2-(4-fluorophenyl)-2-oxoethyl-2-methylprop-2-enoate (PFPAMA), a methacrylate-based synthetic polymer, was prepared by hydrothermal method. Miscibility and compatibility of the CS-PFPAMA blend were confirmed by the single glass transition temperature (T-g) determined by differential scanning calorimetry (DSC). Then, lanthanum hexaboride (LaB6) nanoparticles (NPs) prepared by the chemical method were successfully added to the CS-PFPAMA blend at different weight ratios by hydrothermal method. Morphological characterizations of CS-PFPAMA blend and produced nanocomposites were performed with Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, energy-dispersive X-ray spectroscopy, and atomic force microscopy, and thermal characterizations were made with thermogravimetric analysis and DSC. The thermal stability and T-g values of the obtained CS-PFPAMA blend and nanocomposites were lower than the values of the CS. However, LaB6 NPs increased the dielectric properties of the CS-PFPAMA blend. Thus, the potential use of the produced nanocomposites in electronic devices may be in question. According to the results of antibiogram tests performed by the disk diffusion method, it was determined that nanocomposites showed a serious resistance against Escherichia coli and Staphylococcus aureus pathogens. In addition, both antioxidant and oxidant properties of nanocomposites showed values close to the reference material used. The determined biological properties indicate that the CS-based nanocomposites can be used as biomaterials.
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    Preparation of Novel Composites of Polyvinyl Alcohol Containing Hesperidin Loaded ZnO Nanoparticles and Determination of Their Biological and Thermal Properties
    (Springer, 2023) Erol, İbrahim; Hazman, Ömer; Aksu, Mecit
    Hesperidin (HSP) is considered to be the most effective antimicrobial agent against SARS-CoV2 virus. The HSP was loaded onto ZnO nanoparticles that were successfully incorporated, via the hydrothermal method, into polyvinyl alcohol (PVA) for use as food packaging material. The hydrothermal method enabled the bioactive ZnO-HSP to be homogeneously dispersed in the PVA, which significantly increased the thermal stability of the matrix, while decreasing the softening temperature. The water holding capacity and water solubility of the obtained nanocomposites was reduced compared to the PVA. Finally, the ZnO-HSP antimicrobial agent contributed important antibacterial properties to the PVA and increased its antioxidant capacity against Staphylococcus aureus and Escherichia coli pathogens. In addition, the nanocomposites had no cytotoxic/proliferative effects on cancer cells. All results showed promise that the PVA/ZnO-HSP nanocomposites would be an excellent alternative for food packaging applications.
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    Preparation of poly(AAm-co-HEMA)/ZnO nanocomposites via in situ polymerization/hydrothermal method and determination of their properties
    (Springer, 2022) Erol, İbrahim; Aksu, Mecit; Gürler, Zeki
    In this study, nanocomposites of acrylamide (AAm) and 2-hydroxyethyl methacrylate (HEMA)-based hydrogel containing ZnO nanoparticles in different ratios by mass (1, 3, and 5%) were synthesized using in situ polymerization/hydrothermal method. It was determined that the hydrogel contained 60% HEMA in the copolymer composition calculated with the help of H-1-NMR. Characterization of materials was carried out by SEM, BET, FTIR, UV-Vis, TGA, and XRD techniques. The Ea and Tg value and thermal stability of the pure poly(AAm-co-HEMA) hydrogel were increased by adding ZnO. The water absorption capacity of nanocomposites was determined by swelling experiments. As the amount of ZnO in the composites increased, the degree of swelling decreased. Biological activities of poly(AAm-co-HEMA) and nanocomposites against gram-positive (S. aureus) and gram-negative (E. coli) bacteria increased as the amount of ZnO increased. Finally, The dielectric properties of the poly(AAm-co-HEMA) and nanocomposites were investigated as a function of frequency at 25 degrees C temperature in the frequency range of 1-200 kHz.
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    A study on the investigation of gamma shielding properties of some metal borides
    (Elsevier Ltd, 2019) Gülbiçim, Hasan; Türkan, M. Nureddin; Aksu, Mecit; Durmuş, Sefa
    In this study, the gamma radiation absorption capabilities of some metal borides were studied by using Monte Carlo simulation method. So, the mass attenuation coefficients, ? m , the half value layer, HVL, the tenth value layer, TVL and the mean free path, MFP values of the NdB 6 , SmB 6 and GdB 6 were calculated by means of EGSnrc particle transport code and XCOM program theoretically within the energy range 0.125–5 MeV. It was seen that there is a quite successful consistency (t = 0.00049, p = 0.99961) between the simulated results and calculated values obtained by NIST's XCOM photon cross-section database. Those computational results for the synthesized compounds have also been compared with lead and vermiculite which have concluded that NdB 6 , SmB 6 , and GdB 6 are good candidates for gamma shielding applications. These materials were sythesized by magnesiothermic reduction in open air. Stoichiometric amounts of M 2 O 3 , B 2 O 3 and Mg (20% excess) were mixed, where M III is a lanthanide metal (Nd III , Sm III and Gd III ) ion. Mixture was heated to 700 °C, 800 °C and 900 °C. Optimum reaction temperature and reaction time were found by X-Ray Diffraction (XRD) analysis and Scannning Electron Microscopy (SEM). By fixing the reaction temperature, reaction time has changed as 1, 2, 3, 4 and 5 h to obtain nano crystals with homogeneous morphology. It was found that optimum reaction temperature and reaction time of NdB 6 is 700 °C and 3 h, for SmB 6 700 °C and 1 h for GdB 6 900 °C. © 2019
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    Synergistic effect of ZnO nanoparticles and hesperidin on the antibacterial properties of chitosan
    (Taylor & Francis Ltd, 2022) Erol, İbrahim; Hazman, Ömer; Aksu, Mecit; Bulut, Emine
    In this study, hesperidin (HSP) biological agent, which has strong antioxidant properties, was successfully transferred to ZnO nanoparticles, which were first synthesized by the hydrothermal method. Then, chitosan (CS)/ZnO-HSP nanocomposites were produced by adding different ratios of the ZnO-HSPs to the biodegradable CS biopolymer by hydrothermal method. The resulting materials were characterized using various biophysical strategies, including X-ray diffraction (XRD), Fourier transform infrared spectrometry, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy. The mean particle size of ZnO was estimated to be 29 nm from the XRD calculations and SEM measurements. The effect of the ZnO-HSPs on the thermal properties of pure CS was investigated by thermogravimetric analysis and differential scanning calorimetry techniques, and improvements were noted in the thermal properties of CS. While the T-g value of CS was 81 degrees C, this value increased by 13-94 degrees C with the addition of 6 wt% by weight of the ZnO-HSP. The antibacterial effect of materials was determined by the disc diffusion method. The ZnO-HSPs added to the CS caused the nanocomposites to have a remarkable effect against Escherichia coli and Staphylococcus aureus microorganisms. While the inhibition diameter of the CS against E. coli was 18.3, the same value increased to 22.3 for the composite containing 6 wt% the ZnO-HSP. The HSP increased the antioxidant capacity of both the ZnO-HSP particles and the CS/ZnO-HSP nanocomposites, reducing the toxic effects of ZnO nanoparticles. Thus, it was determined that the CS/ZnO-HSP nanocomposites did not have any cytotoxicity in healthy human cells. The fact that the produced nanocomposites exhibit antibacterial activity and do not harm human cells shows that they can be a safe product for health. From all these results, this triple hybrid system is hoped that it will be used in biomedical applications as a naturally-sourced, environmentally friendly, and cost-effective composite biomaterial by combining its antimicrobial and strong antioxidant properties.
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    Synthesis and DFT study of Cd(II) and Hg(II) complexes of ONNO-type Schiff bases
    (Taylor & Francis Inc, 2017) Aksu, Mecit; Çifci, Mehmet; Böyükata, Mustafa; Durmuş, Sefa; Babgi, Bandar
    This study consists of the synthesis of cadmium (II) and mercury (II) metal complexes of ONNO-type Schiff bases. Two different ONNO-type Schiff bases were prepared. One cadmium(II) and one mercury(II) complex of the considered Schiff bases were achieved. Both are proved to be mononuclear complexes. Ligands and complexes were analyzed via melting point determination, elemental analyses, thermogravimetric (TG) analysis, infrared (IR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. Moreover, structural and energetic analyses for both complexes have been realized using Hartree-Fock (HF) and density functional theory (DFT) methods with CEP-121G basis set.
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    Synthesis of Moringa oleifera coated silver-containing nanocomposites of a new methacrylate polymer having pendant fluoroarylketone by hydrothermal technique and investigation of thermal, optical, dielectric and biological properties
    (Taylor & Francis Ltd, 2022) Erol, İbrahim; Ciğerci, İbrahim Hakkı; Özkara, Arzu; Akyil, Dilek; Aksu, Mecit
    Firstly, silver nanoparticles were synthesized by green synthesis method from Moringa oleifera extract. Nanocomposites containing newly synthesized methacrylate polymer, poly 2-(4-fluorophenyl)-2-oxoethyl-2-methylprop-2-enoate (PFPAMA) and Ag nanoparticles from M. oleifera in different mass ratios (1, 3, and 5 wt%) were synthesized using the hydrothermal method. The morphological and structural properties of the materials have been examined by SEM, FTIR, UV, TGA, and XRD techniques. The activation energies (E-a) related to thermal decomposition of the nanocomposites were estimated by the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods by using non-isothermal TGA experiments. The thermal stability, glass transition temperature (T-g), and the thermal decomposition activation energy (E-a) values of nanocomposites were increased by increasing the Ag nanoparticles amount on the composite. The dielectric constant (epsilon '), the dielectric loss factor (epsilon '') and ac conductivity of neat PFPAMA and nanocomposites were also measured for the frequency range of 100 Hz to 2 kHz at 25 degrees C. It was seen that the frequency dependence of the dielectric constant and dielectric loss factor decreased with increasing frequency. The biological activities of nanocomposites against gram-positive (Staphylococcus aureus), gram-negative (Escherichia coli) bacteria and Candida krusei yeast were also tested. The antibacterial effect increased against both bacterial species as the amount of Ag nanoparticles from M. oleifera in the nanocomposites increased. In addition, the wound healing properties of nanocomposites were investigated by the scratch wound test.