Determination of Phenolic Compounds in Wine: A Review

One of the main constituents in wines is the phenolic compounds that comprise the phenolic acids, flavonoids, lignans and stilbenes. Those have an important paper on the wines properties like flavor, appearance, astringent and antimicrobial properties. Moreover, phenolics have been extensively study in having antioxidant properties that may help in the prevention of disease like certain types of cancer, cardiovascular diseases, diabetes, strokes and other diseases related to aging. So is important the development of the phenolic compounds determination methods to be more selective, fast and easy operation. This paper brings a review of the methods employed on phenolics determination until this year

Modified sol-gel synthesis of lithium ternary oxide

Lithium-ion batteries currently equip portable electronic devices, such as smartphones and laptops, and are the choice to power electric vehicles. The scarcity of raw materials in nature, however, has required the development of new technologies and the ternary lithium compound LiNi1/3Mn1/3Co1/3O2 has stood out as an alternative for replacing part of the cobalt in LiCoO2 by nickel and manganese, which are more abundant, reducing the electrode’s cost. The sol-gel route for synthesis of ternary electrode materials has been widely used, but it faces problems of volumetric expansion due to the decomposition of organic material during calcination. To improve the synthesis of the ternary compound, a modified sol-gel route with control of the heating kinetics in the pre-calcination step and without pH control was investigated in this study. The compound was analyzed by X-ray diffraction, Rietveld refinement, Fourier transform infrared absorption spectroscopy, and Raman that showed the purification of the ternary phase with appropriate crystallinity for application as electrode in batteries from 700 ºC. In conclusion, ternary synthesis with rate control during heat treatment may be a useful alternative for industrial scale-up production

Methylene blue photocatalysis in the presence of bismuth oxide under UV and solar light irradiation

Bismuth oxide (Bi2O3), an n-type semiconductor has been satisfactorily investigated for photocatalytic organic contaminant remediation. The Bi2O3 was prepared by solution combustion synthesis (SCS) using as the oxidizing bismuth nitrate in acidic medium and urea as fuel. The influence of the type of synthesis on the photocatalytic properties of the oxide formed was investigated by XRD. From the diffractograms was verified that the materials obtained are predominantly of Bi2O3 crystals, it is possible to identify a sample with two crystalline phases, monoclinic (α-Bi2O3) and tetragonal (β-Bi2O3), and the other with only the monoclinic (α-Bi2O3). The two-phase oxide showed higher photocatalytic activity for discoloration of methylene blue under UV irradiation (60.59%) and under sunlight (61.64%) in 664 nm, followed kinetic law of pseudo-first order