Stability against color fading of azo dyes encapsulated in Ca-aluminosilicate mesoporous substrates

Light-fastness properties of composites involving mesoporous calcium-modifi ed aluminosilicate substrates (MCM-41 structure) and dye (Lithol Rubine B) were examined. High surface area A1-MCM-41 materials synthesized in the pre sence of Ca2+ ions proved efficient hosts for Lithol Rubine B, yielding mes ophase-dye composites with the highest light-fastness qualities, when compa red to Ca-exchanged Al-MCM-41 aluminosilicates, to non composite pigment or to smectite-dye composites. The marked resistance of the new composites to fading was attributed to an optimized Cadye interaction favored by a contr olled heating the Ca(OH)(2)-loaded mesoporous precursors, yielding tiny CaO particles, highly dispersed and retained onto the large internal surface o f the substrate. (C) 2001 Elsevier Science B.V. All rights reserved.