SOL-GEL SYNTHESIS NaCrSi_2O_6 NANOPIGMENTS AIDED BY STATISTICAL DESIGN OF EXPERIMENTS

摘要

The synthesis of ceramic nanopigments by non-conventional methods: Sol-Gel technical aided by use of statistical techniques has aroused interest to new colour pigments. In the present work, the mixture experiments was used to evaluate the influence of precursors (sodium silicate, chromium nitrate and colloidal silica) mixture sol-gel process on the main colorimetric properties (evaluated as L~*, a~*, b~* coordinates color); it used to mixture design reticular lattice simplex with replies at centre point to analyst. The powders of NaCrSi2O6, obtained by sol-gel method and process by one-firing at 850℃; the samples were characterised by X-ray Diffraction (XDR), Scanning Electron Microscopy (SEM), UV-Vis Spectroscopy by diffuse reflectance method and CIE-L~*a~*b~* colour parameters. The colour performance of raw powders obtained by non-conventional methods in glazed stoneware improves that of ceramic samples fired at 1100℃ used as reference. Particle size of the nanoparticles obtained by the spinel structures was less 100nm.