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Carbon-based structures have attracted attention due to their unique properties, combining excellent chemical, thermal mechanical, and electrical features. The use of microwave irradiation has been used to produce graphene materials and the identification of optimum synthesis parameters is crucial for the production of high-quality carbon structures. Herein, we describe a detailed temperature study for the production of expanded graphite nanosheets (GNs) via intercalation of sulfuric and nitric acids, followed by a rapid and energy-efficient process of microwave-assisted expansion and exfoliation. The results demonstrate that the proposed methodology was efficient in producing high-quality GNs with a size of approximately 1 nm. The temperature investigation revealed that heat treatment of 800 °C was the best, resulting in a high-quality material, achieving maximum expansion with the lowest weight loss related to thermal degradation. Thus, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests confirmed good electrochemical features of the sample produced at a temperature of 800 °C. [ABSTRACT FROM AUTHOR]

The radiological protection has the purpose of safeguarding the physical well-being of the user, preventing exposure to detrimental levels of ionizing radiation. This study introduces a novel, cost-effective category of lead-free elastomeric material designed for radiation shielding. The filler compounds utilized are notably lighter than conventional lead-based materials, enhancing user ergonomics during application. They comprise of a blend of barium sulfate combined or not with magnesium oxide with addition-cure liquid silicone rubber. To ensure the effectiveness of the radiation shielding, X-ray transmission measurements were performed for the different thicknesses of the materials and the results compared with Monte Carlo simulations. Additionally, the physical properties of the new materials, such as density, homogeneity, tensile strength, viscosity, and wettability, were also evaluated. The findings indicate that both materials fulfill the requirement for application in radiation protection garments. [ABSTRACT FROM AUTHOR]

In this work, Ag-doped CeO2 samples containing 0.5 mol% Ag+ were successfully synthesized by the polymeric precursor method and then calcined at 400, 500, 600 and 700 °C for 2 h. X-ray diffraction and Raman spectra indicated that the crystals have a fluorite-type structure without the presence of other phases. The size of the Ce0.95Ag0.05O1.9−δ crystals increased from 6.61 to 27.46 nm upon increasing the thermal treatment temperature. The decomposition of the samples was examined by differential thermal analysis to determine the most suitable calcination temperature to apply to the materials and indicate the steps involved in obtaining Ag-doped ceria. Scanning electron microscopy images revealed small crystallite sizes, the presence of oxygen vacancies, structural stability and homogeneity. The Ag-doped ceria have shown effective and efficient antimicrobial activity, inhibiting the growth of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa bacteria. However, pure CeO2 displayed no antibacterial activity. Therefore, the satisfactory antimicrobial activity reported here can be attributed to the partial substitution of cerium ions by silver ions. [ABSTRACT FROM AUTHOR]