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Z. Durmus H. Kavas H. Sozeri M. S. Toprak A. Aslan A. Baykal 《Journal of Superconductivity and Novel Magnetism》2012,25(4):1185-1193
We present a method for the fabrication of PVPA/BaFe12O19 nanocomposite by in-situ polymerization of vinyl phosphonic acid, VPA in the presence of synthesized BaFe12O19 NPs. Nanoparticles and the nanocomposite were analyzed by XRD, FTIR, TGA, SEM, TEM, VSM, and conductivity techniques for structural and physicochemical characteristics. Nanoparticles, identified as BaFe12O19 from XRD analysis, were successfully coated with PVPA and the linkage was assessed to be via P?CO bonds. Electron microscopy analysis revealed aggregation of BaFe12O19 particles and dominantly platelet morphology upon composite formation. TGA analysis revealed the composition of the nanocomposite as 65% BaFe12O19 and 35% polymer. Magnetic evaluation revealed that adsorption of PVPA anions during the preparation of the nanocomposite strongly influenced the magnetic properties resulting in much lower saturation magnetization values. DC conductivity measurements were used to calculate activation energy of PVPA/BaFe12O19 nanocomposite and it was obtained as 0.37?eV. 相似文献
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O. Akman H. Kavas A. Baykal Z. Durmus B. Aktaş H. Sözeri 《Journal of Superconductivity and Novel Magnetism》2013,26(4):1369-1373
This study investigates microwave absorption properties of Ba-hexaferrite (BaFe12O19) and titanium dioxide (TiO2) particles coated with conducting polymer (PANI) and BaFe12O19-TiO2 mixture in the frequency range of 8–18 GHz. Samples having different magnetic to dielectric mass ratios and various thicknesses from 1.5 to 4 mm have been prepared to investigate effect of magnetic and dielectric fillers together with influence of conducting polymer layer on microwave absorption properties of BaFe12O19-TiO2 composite. Structural, magnetic, and microwave absorption properties of composites have been investigated using X-ray diffraction, scanning electron microscopy and near field microwave measurements using vector network analyzer. Microwave measurements revealed that composites with PANI coating have much higher absorption values which are independent of an absorber thickness. Among PANI coated absorbers, sample having magnetic to dielectric mass ratio of 2 showed better microwave properties in 8–18 GHz range. 相似文献
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The study was directed towards determining the usability of clay and fine wastes (CW and FW) of boron from the concentrator plant in Kirka (Turkey) as a fluxing agent in production of red mud (RM) brick. Both laboratory studies on the characterization of materials and industrial-scale tests for production of bricks were carried out. CW and FW, which have similar chemical composition but include different types and amounts of oxides, were added in amounts of 5, 10 and 15 wt% to RM, which consists of high amounts of Fe2O3, Al2O3, SiO2 and alkalies. Six different sets of samples have been produced and fired at 700, 800 and 900 °C. Dry shrinkage of green body, bending and compressive strength, firing shrinkage, water absorption, frost resistance and harmful magnesia and lime tests on heat-treated bodies have been performed. The mineralogical and mechanical tests showed that usability of boron wastes as a fluxing agent in the production of RM bricks was possible. In addition, the samples obtained by adding 15 wt% CW and FW to RM showed the best mechanical characteristic. 相似文献
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Harun Uysal Sevda Kilic Gokhan Kavas Necati Akbulut Harun Kesenkas 《International Journal of Dairy Technology》2003,56(3):177-181
Set yoghurt was produced from caprine milk (A), 70% caprine-30% bovine (B) and 50% caprine–50% bovine milk (C) mixtures, and stored for 14 days at ±4°C. Two methods of fortification, namely ultrafiltration (UF) and the addition of bovine skim milk powder (SMP), were applied to the milk mixtures. Some chemical, physical, microbiological and sensory properties of the six samples were analysed on the 1st, 7th and 14th days of storage. The effects of milk type, concentration method and storage period on the physicochemical and microbiological properties of the samples were investigated statistically. 相似文献
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Luca Sauser Tadeáš Kalvoda Ayça Kavas Prof. Lubomír Rulíšek Dr. Michal S. Shoshan 《ChemMedChem》2022,17(15):e202200152
A rationally-designed scaffold of cyclic octapeptides composed of two units of the natural tripeptide glutathione (GSH) was optimized to strongly and selectively capture toxic lead ions (Pb(II)). Using state-of-the-art computational tools, a list of eleven plausible peptides was shortened to five analogs based on their calculated affinity to Pb(II) ions. We then synthesized and investigated them for their abilities to recover Pb-poisoned human cells. A clear pattern was observed from the in vitro detoxification results, indicating the importance of cavity size and polar moieties to enhance metal capturing. These, together with the apparent benefit of cyclizing the peptides, improved the detoxification of the two lead peptides by approximately two folds compared to GSH and the benchmark chelating agents against Pb poisoning. Moreover, the two peptides did not show any toxicity and, therefore, were thoroughly investigated to determine their potential as next-generation remedies for Pb poisoning. 相似文献
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H. Kavas M. Günay A. Baykal M. S. Toprak H. Sozeri B. Aktaş 《Journal of Inorganic and Organometallic Polymers and Materials》2013,23(2):306-314
Polyaniline–Fe3O4 nanocomposite with and without ionic liquid were successfully synthesized via in situ polymerization using cetyl trimethylammonium bromide (CTAB) as surfactant. Both TG analysis and FT-IR measurements proved the presence of organic layer on the surface of Fe3O4 nanoparticles. The influence of 1-butyl-3-methyl-imidazolium bromide (BMIMBr) as ionic liquid on the structure, conductivity, and magnetic property of PANI–Fe3O4–CTAB nanocomposite were studied in detail. The results show that imidazolium-based ionic liquids BMIMBr acts as an anchor agent during the formation of PANI–Fe3O4–CTAB nanocomposite. Ionic liquid significantly deteriorated nanocomposite’s magnetic properties, and contributed to non-saturated M–H curve due to the disappearance of antiferromagnetic interactions. It has also an improving effect on AC and DC conductivities. The most important effect of IL is observed in real part of permittivity of PANI–Fe3O4–CTAB that it has negative high values at low frequency low temperature region. Due to the negative dielectric constant, material exhibits uncommon properties in electromagnetic waves scattering and attraction between similar charges. This possibility provokes research on these composites as high T superconductors, negative index materials and microwave absorbers. 相似文献
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Nano-Micro Letters - A PEG assisted hydrothermal route was used to study the influence of the hydrolyzing agent on the properties of PEG-iron oxide (Fe3O4) nanocomposites. Iron oxide nanoparticles... 相似文献
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The effect of BaCO3 (witherite) addition on the sintering behavior of lignite coal fly ash taken from the Seyitömer power plant of Kütahya/Turkey was examined at temperatures of 1100, 1150 and 1200 °C in air atmosphere. Bloating of the fly ash samples sintered at 1150 °C was prevented, that is, the decomposition temperature of CaSO4 in the fly ash is shifted to a higher temperature, and their physico-mechanical properties (porosity, water absorption, bulk density and bending strength) were improved with BaCO3 addition. Positive effects of BaCO3, however, were not seen on the fly ash samples sintered at 1100 °C. All the fly ash samples sintered at 1200 °C were bloated due to the gas evolving and also they melted. During the thermal treatment at 1150 °C a phase transformation from CaSO4 (anhydrite) to BaSO4 (Barite) occurred in the fly ash with BaCO3 addition as seen from the X-ray diffraction (XRD) patterns and the bar shaped fly ash samples with BaCO3 saved their structural integrity up to 1150 °C. 相似文献