Síntesis y propiedades ópticas y coloidales de un sistema híbrido arcilla/colorante orgánico (original) (raw)

Hybrid nanopigments are intercalation compounds formed by cationic organic dyes adsorbed on the surface of, mainly, smectite clay mineral hosts. In the present research project it is exposed a methodology oriented to the synthesis and characterization of this kind of materials with the aim to estimate the main effects and interactions of some synthesis factors on its colloidal and optical properties, as potential coloration alternatives in cosmetics, inks and paints. Using a factorial design for the experiments, the considered factors in the synthesis process were the ionic strength in the solution, the clay concentration and the clay/dye ratio. The response variable to obtain a regression model was the particle size distribution obtained by means of Dynamic Light Scattering. As an innovative approach, it was identified the formation of molecular dye aggregates by means of absorbance spectroscopy and it was correlated with the dispersion structural properties. It is demonstrated that the increase in the clay and salt concentration, as the decrease in the dye concentration, promotes the formation of larger clay aggregates. Besides, it is correlated the formation of some dye spectral species with the clay aggregates size and the inorganic cations content.