Saponite-anthocyanin pigments: slipping between the sheets

Abstract The present work describes the synthesis and characterization of hybrid materials based on β-cyclodextrin (β-CD) and cetyltrimethylammonium bromide (CTAB) intercalated into saponite (SAP) and a commercially available powder of anthocyanin dye, Crystal Red Grape (RG). The interactions between the organic dye guest and the organo-clay host were investigated by X-ray diffraction, thermogravimetric analysis, transmission electronic microscopy and 13C solid state nuclear magnetic resonance. The results support complex formation between β-CD and CTAB, their intercalation into the clay interlayer spaces or surface loading, and their interaction with RG (CTAB_SAP-RG, β-CD_SAP-RG and β-CD+CTAB_SAP-RG). The hybrid pigments formed exhibit different colors, enhanced stability against visible light irradiation and basic pH conditions. These hybrid pigments are environmentally friendly and can be promising candidates in different application fields.