Abstract
Hybrid pigments based on carminic acid (CA) stabilized by clay minerals have been prepared. Three different pathways were used: CA@saponite; CA@Al-pillared saponite; and hydrogels of saponite-CA or montmorillonite-CA covered by polyorganosilane (POS). Pigments were characterized by a set of different techniques including X-Ray diffraction (XRD), transmission electron microscopy (TEM), infrared spectroscopy (FTIR), solid state nuclear magnetic resonance (NMR) and time-resolved fluorescence (TRF) spectroscopies. The color parameters, i.e., L*a*b*, were measured. In addition, the photostability of the samples under visible light was evaluated. The results showed that CA@PilSap presented a greater stability compared to CA@Saponite. The pigments obtained from hydrogels presented the greatest light stability due to the coverage with POS that acts as a protective layer.