2011 Volume 84 Issue 9 Pages 308-312
2-Hydroxy-4'-methoxychalcone (HMC), a synthetic anthocyanin dye, has the same molecular skeleton as plant pigments and is promising as a safe and environmentally friendly photochromic material. With the objective of using the HMC dye under dry conditions, a composite of Al containing mesoporous silica (Al-MPS) and HMC dye was prepared, and its photochromic properties were investigated. The composite of Al-free MPS had a vivid yellow appearance ; the color disappeared within seven days on storage in darkness at 313 K and 95% RH. Its color strength recovered to 50% of the initial value on UV-A irradiation, demonstrating the coloring-discoloring process. Incorporation of Al into MPS increased the quantity of HMC dye adsorbed onto it; however, the discoloring process from the FV+ form (yellow) to the t-C form (non-color) of the dye occurred with some difficulty.
