A direct-doping method was tested to design new composite-glasses by incorporating lanthanum niobate nanocrystals (NC) in tellurite glasses. NC powder were grinding with glass powder before heating-quenching, with the main investigation approached of best parameters for NC suitable homogenization but limited dissolution. Thermal analysis signalizes that prior heat-treatment of NC promotes higher transparency and limits NC dissolution. These materials with visually detectable NC aggregates exhibited glass transition temperatures close to the starting glass. LaNbO4 phase was hardly detected by X-ray diffraction because of the low weight ratio and partial dissolution but the monoclinic polymorph could be identified for lower time. UV-visible-NIR transmission spectra also related progressive lower transparency with light scattering of NC aggregates. Photoluminescence suggest that lower times allowed to ensure the NC environment with lower crystallinity around Eu3+-ions in final composite-glass. These results pave the way for designing new materials containing NC not achievable by conventional nucleation-growth methods. directdoping direct doping compositeglasses composite glasses (NC heatingquenching, heatingquenching heating quenching, quenching heating-quenching heattreatment heat treatment LaNbO Xray X ray time UVvisibleNIR UV visible NIR Eu3+ions Eu3ions Euions Eu3+ ions Eu3 Eu compositeglass. compositeglass composite-glass nucleationgrowth nucleation growth methods

Temperature is a natural phenomenon that may modify the structure of chemical compounds and hence their properties. We aimed to develop a simple portable system based on the Peltier principle for spectral characterization of compounds with temperature-dependent structure. The device was constructed and adapted to three pieces of equipment: X-ray diffractometer, vibrational spectrophotometer, and electronic spectrophotometer. The device was evaluated by using commercial thermochromatic inks, whose color depends on temperature. The X-ray diffraction results for the ink whose color changed at a transition temperature of 31 oC showed that the peak at 2θ = 21.6o decreased probably due to alterations in the structures of the components underlying the ink color and solvent. The absorption spectra showed reduced absorption, typical of change in color, a property that is inversely proportional to temperature. The device working range varied from 15 to 75 oC, and it was constructed from parts that are easily available in the national market at an affordable price. The device can be adapted to different equipment with distinct configurations regarding the sample compartment.

THE USE OF HYBRID OR NANOCOMPOSITE MATERIALS AS STEEL ANTICORROSIVE COATINGS. The search had as the goal to present and reflect the hybrid materials as an alternative for anticorrosive coatings of metallic surfaces, such as steel. For comparison purposes, different types of anti-corrosion coatings capable of protecting metallic surfaces, such as steel, from oxidation action were presented. Steel is a metallic material widely used by industry in different types of segments, and its corrosion is a pathology responsible for its functional loss, causing losses in its use. Through a qualitative, bibliographic and exploratory research, based on academic works, it was presented that hybrid materials or nanocomposites prove to be efficient as anticorrosive coatings capable of protecting steel against oxidation.

In this work titanium sol was prepared from tetraethylorthotitanate (TEOT) in ethanol, stabilized with beta-diketonate 2,4 pentanedione in molar ratio 1:1 homogenized by magnetic stirring, europium ion was add as structural probe. The xerogels were heat treated at 500, 750 and 1000 °C and the characterization was realized by x-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA/DSC) and photoluminescence (PL). The excitation spectra of Eu (III) ion present maximum in 394 nm correspondent to 5L6 level and emission spectra present bands characteristic transitions arising from the 5 D0 -> 7F J (J = 0, 1, 2, 3, 4) manifolds to samples treat at 500 and 750 °C. The Eu (III) emission disappear, when heated at 1000 °C, probably due to phase transition anatase to rutile and migrations of ions to the external surface that was proved by x-ray diffraction, transmission electronic microscopy and the thermogravimetric analyses of xerogels.