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Methylene blue is widely used in various industries, such as textile. Notably, wastewater generated from these industries represents a significant source of water pollution. To solve this problem, the use of photocatalysts for the degradation of methylene blue in wastewater has attracted the attention of many researchers. In this study, manganesezinc ferrite nanoparticles doped with dysprosium with the chemical composition of Mn0.8Zn0.2Fe1.95Dy0.05O4 were utilized as photocatalyst for the degradation of methylene blue dye. Initially, the nanoparticles were synthesized using a self-combustion sol-gel method, and their phase composition and microstructural characteristics were evaluated through X-ray diffraction and field emission scanning electron microscopy, respectively. The XRD patterns confirmed the formation of manganese-zinc ferrite nanoparticles with an average crystallite size of 28.38 nm within a spinel structure. Additionally, FE-SEM micrographs indicated an average particle size of approximately 99.28 nm for the nanoparticles. Subsequently, the influence of different values of the synthesized manganese-zinc ferrite nanoparticles (0.0, 0.1, 0.2, and 0.3 g/lit) on the degradation of methylene blue dye was investigated. The results demonstrated that the presence of these nanoparticles significantly affected the degradation rate of methylene blue. Ultimately, the findings indicated that the addition of 0.1 g/lit of these nanoparticles yielded the most effective results, achieving approximately 87.25% degradation in 12 h. [ABSTRACT FROM AUTHOR]

In the present research, alumina-ceria particles were synthesized by a sol-gel method. The produced particles were characterized by X-ray diffraction and scanning electron microscopy. Then, alumina matrix composites containing 15 wt.% of ceria were densified under 80 MPa pressure at different temperatures by spark plasma sintering process. X-ray diffraction results showed that the powder produced before heat treatment has an amorphous structure, while alumina and ceria phases are formed after calcination at 800 °C. The produced particles have an average particle size of 250 nm. The effect of sintering temperature on the density of samples, grain size, and hardness of composites was investigated. The samples were densified at about 1400 °C, reaching a density of about 97% of the theoretical density. The microstructure analysis revealed that the composite grains have grown with increasing sintering temperature. The results declared that increasing the temperature and pressure in the sintering process enhances the density of the samples. The Vickers hardness of the composites increased with increasing sintering temperature, as the composite samples sintered at 1400 °C for 20 minutes at a pressure of 80 MPa had the highest Vickers hardness of about 15.3 GPa. [ABSTRACT FROM AUTHOR]

Strontium hexaferrite M-type nanoparticles doped with La and Cu (SrFe12-xCuxO19-Sr1-xLaxFe12-xCuxO19) with different mole fractions (x=0.1-0.2-0.3-0.4-0.5) synthesized by self-combustion sol-gel technique. Firstly, a gel of metal nitrates with the above-mentioned mole fractions were fabricated and the obtained powder was cured at 950°C. Microstructural properties and the morphology of the compounds were investigated by employing X-ray diffraction (XRD) and scanning electron microscopy (SEM). Also, in order to investigate the magnetic properties, Vibrating Sample Magnetometer (VSM) was used. SEM images revealed that the particles had an average size of about 100 nm. Cu2+ ions were substituted with Fe3+ ions within the crystalline sites of SrFe12O19 structure. It was shown that the lattice parameter (a) remained approximately unchanged with an increase in Cu-dopped while the lattice parameter (c) decreased with increasing the mole fraction (x). By using VSM hysteresis diagrams, it was observed that the saturated magnetization and coercive force increased with the addition of La; this was attributed to the variation in the distribution of ions and the shape anisotropy of the nanoparticles. These significant changes in the magnetic properties were for the sample with the composition of Sr1-xLaxFe12-xCuxO19 and SrFe12-xCuxO19, for the x=0.1 and x=0.5, respectively. [ABSTRACT FROM AUTHOR]

Mn0.8Zn0.2Fe2-xDyxO4 (where x= 0, 0.025, 0.05, 0.075, 0.1) ferrite nanoparticles were synthesized by auto-combustion sol-gel method for the first time in this study. The effect of Dy-doping on the structural and magnetic properties of the produced specimens was examined using the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometery (VSM), and field emission scanning electron microscope (FE-SEM). The results showed that a cubic spinel structure was formed in all of the synthesized specimens. It was also found that the addition of Dy increased the lattice parameter while decreased the average of crystallites size. Furthermore, the FE-SEM micrographs showed that Dy not only plays an effective role in reducing the agglomeration of nanoparticles and their distribution, but also reduces the average of particle size. It was also observed that the addition of Dy had no effect on the morphology of the synthesized nanoparticles. Investigation of the magnetic properties revealed a clear decrease in the saturation magnetization and coercivity by the Dy addition. So that the saturation magnetization of the samples decreased from 66.3 to 58.4 emu/g and the coercivity decreased from 78.5 to 71.9 Oe. [ABSTRACT FROM AUTHOR]

In this research, barium calcium hexaferrite (Ba1-xCaxFe12O19, 0≤x1) nanoparticles were synthesized through a sol-gel combustion method. The dried gel samples were then calcined at 950ºC for 4:30h. The phase and microstructural evolution of calcined samples were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results revealed formation of calcium -barium hexaferrite phase with a small amount of hematite as a secondary phase. The average particle size is between 60-100 nm and the particle morphology is hexagonal or plate like structure. Results of a vibrating sample magnetometer (VSM) showed that the sample with x=0.4, exhibited the lowest value of saturation magnetization in comparison with others. This could be due to structural heterogeneity and presence of higher amounts of non- magnetic phases (BaFe2O4 and Fe2O3) in this sample compared to others. The results of sensory testing in acetone gas showed that the barium-calcium hexaferrite sample with x=0.2 had the highest sensitivity (0.28) and shortest response (15s) at a concentration of 900 ppm and a temperature of 200 °C despite of the long recovery time. [ABSTRACT FROM AUTHOR]

In this study, adsorption of fluconazole on silica aerogel was performed successfully by the immersion method in the 1% solution of fluconazole-ethanol at the ambient condition and without using the supercritical method. The hydrophobic and hydrophilic silica aerogels were synthesized by the two-stage sol-gel method and dried at the ambient temperature. This method had most of drug loading at 24 h. It was 1.92% and 1.98% for the hydrophilic and hydrophobic silica aerogels, respectively. Physical properties of the synthesized aerogels were studied by the nitrogen absorption and desorption tests. The presence of fluconazole and the chemical structure of the samples were determined by fourier-transform infrared spectroscopy (FTIR). As well, the loading and release of the drug were investigated using a spectrophotometer. The results showed the structure of the synthesized aerogels had a pore diameter of 6-8 nm and a surface area of about 800-100 m2/g. The study of the drug release also revealed that the release rate of fluconazole in the hydrophilic silica aerogel was higher than that of the hydrophobic sample. [ABSTRACT FROM AUTHOR]