abstractCoAl2O4 pigments were synthesized through Liquid-Feed Flame Spray Pyrolysis (LF-FSP) method using metallorganic precursors of cobalt propionate and alumatrane. The precursors were dissolved in ethanol and aerosolized into a methane/oxygen flame where it was combusted to result in nanopowders at a single step. The resulting nanopowders were collected in electrostatic precipitators and analyzed by x-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), colorimetry, Field Emission Scanning Electron Microscopy (FE-SEM) and BET (Brunauer-Emmett-Teller) nitrogen adsorption. Results show formation of single phase blue nanopigments, suggesting that LF-FSP is an excellent method to produce nanoparticles with high quality in a continuous process for new industrial applications. The nanoparticles presented spherical morphology with specific surface area of 50 m2/g, corresponding to average particle size of 27 nm. The pigments were calcined at 500, 600, 800, 1000, 1200 and 1300 °C, aiming to find the color stability whereby the colors were measured using the color space CIE L*a*b* under standardized D65 light. The brightest and bluest was obtained at calcination temperature of 1200°C and its application into a glaze was carried out at 1200 °C to evaluate the color performance and stability after a decoration process. Finally, LF-FSP produced pigments were compared with those produced by solid state reaction. Differences in the color due to the average particle size and process conditions were observed. It is possible to obtain new hues for ceramic applications by LF-FSP method.

We have developed a method to obtain polymer hybrids with control of inorganic content and molecular configuration. Hybrid poly(methyl methacrylate) (PMMA) was obtained via atom transfer radical polymerization (ATRP) initiated by octafunctional cubic silsesquioxanes using CuCl as catalyst. Two different ATRP initiators obtained by attaching specific chemical groups to the cubic silsesquioxane were employed to produce two types of hybrids with different architectures. While a-bromide ester groups generated a star-shaped polymer, the benzyl chloride groups produced longer and more linear polymeric chains containing the cubic silsesquioxane. These results were explained on the basis of the low initiation efficiency of benzyl chloride groups for PMMA, leading to polymers with molecular weights (Mn) and polydispersities (PDI) higher than the expected ones.