Sol–gel synthesis of Mn2O3/Al2O3/SiO2 hybrid nanocomposite and application for removal of organic dye

Journal of Sol-Gel Science and Technology - Nanocomposite of Mn2O3/Al2O3/SiO2 was prepared through an in situ sol–gel process, in which Mn2O3 nanocrystals were dispersed in the silica-alumina...     

ZnO–CdO nanocomposite: microemulsion synthesis and dye removal ability

Journal of Sol-Gel Science and Technology - In this study, Zinc Oxide (ZnO)–Cadmium Oxide (CdO) nanocomposite has been synthesized by reverse microemulsion method and used as adsorbent to...     

Synthesis,characterization, and in vitro toxicity evaluation of upconversion luminescence NaLuF4:Yb3+/Tm3+ nanoparticles suitable for medical applications

Synthesis, characterization, and in vitro toxicity evaluation of upconversion luminescence NaLuF₄:Yb³⁺/Tm³⁺ nanoparticles (UCLNPs) are reported in the current study. Initially, the synthesized lanthanide trifluoroacetate (Ln(OOCCF₃)₃) precursor was used to fabricate NaLuF₄ nanoparticles doped with Yb³⁺ and Tm³⁺ metal ions. The nanoparticles were coated with calcium carbonate (CaCO₃) after removing the hydrophobic species on them to enhance their biocompatibility. The in vitro methylthiazolyldiphenyl-tetrazoliumbromide (MTT) test was used to evaluate the toxicity of synthesized NaLuF₄:Yb³⁺/Tm³⁺ nanoparticles (NLF-5) on L929 mouse fibroblast cell lines. The transmission electron microscopy image showed that the particle size of NaLuF₄:Yb³⁺/Tm³⁺ was 32 nm. The synthesized NLF-5 nanoparticles have both α-cubic and β-hexagonal crystalline structures that provided a superb near-infrared-to-near-infrared upconversion luminescence signal when excited at 980 nm. MTT test results show that the death of L929 fibroblast cells was observed only at concentrations above 250 μg/mL of NaLuF₄:Yb³⁺/Tm³⁺ nanoparticles. In addition, with an increase in patrol time of 24, 48, and 72 hr, cell toxicity increased significantly, while the coated nanoparticles did not have any toxic effects. The synthesized nanoparticles could be used as a suitable material for medical applications due to their small particle size, high photoluminescence emission intensity, and low toxicity.     

Synthesis of the novel CuAl2O4–Al2O3–SiO2 nanocomposites for the removal of pollutant dye and antibacterial applications

Research on Chemical Intermediates - CuAl2O4–Al2O3–SiO2 nanocomposites with different amounts of CuAl2O4 (40, 50, 60 and 70 wt. %) were synthesized by the sol–gel method and...     

Optimization of the synthesis parameters of high surface area ceria nanopowder prepared by surfactant assisted precipitation method

Response surface methodology (RSM) has been used to optimize the critical parameters responsible for higher surface area of ceria nanopowder prepared by surfactant assisted precipitation method. A three-level central composite design (CCD) was used to optimize pH, CTAB/metal molar ratio and calcination temperature. A quadratic model between response and the independent parameters was developed and the response surface model was tested with analysis of variance (ANOVA). The optimum operating conditions determined were a pH value of 9.4, CTAB/metal molar ratio of 0.5 and calcination temperature of 266 °C. Under these optimal conditions maximum surface area of 158 m²/g has been achieved.     

Modeling and optimization of densification of nanocrystalline Al<Subscript>2</Subscript>O<Subscript>3</Subscript> powder prepared by a sol–gel method using response surface methodology

Response surface methodology (RSM) based on central composite design (CCD) was successfully applied to the optimization and modeling of densification of nanocrystalline Al₂O₃ powder prepared by sol–gel method. The effects of three operating variables, sintering temperature, calcination temperature and milling time on the densification of nanocrystalline Al₂O₃ were systematically evaluated. A quadratic model for densification was proposed. Analysis of variance (ANOVA) indicated that the proposed quadratic model could be used to navigate the design space. The simulated values obtained from the statistical model were in conformity with the experimental results within an average error of ±1.5%. The optimum operating conditions for densification were found to be 1,579 °C of sintering temperature, 909 °C of calcination temperature and 117 min of milling time. The obtained density under the optimum conditions determined by RSM was 98.5%. The results confirmed that RSM based on central composite design was an accurate and reliable method to optimize the densification conditions of nanocrystalline Al₂O₃ powder.