The generic enhancement of photochromic dye switching speeds in a rigid polymer matrix

The generic enhancement of photochromic dye switching speeds in a rigid polymer matrix by the attachment of flexible oligomers having a low glass-transition temperature was analyzed. The greatest impact was observed in the thermal fade parameters T_1/2 and T_3/4, the time it takes for the optical density to reduce by half and three quarters of the initial optical density of the colored state. It was shown that the method does not alter the electronic nature of the dyes instead it protects them from the host matrix and provides greater molecular mobility for the switching process. It was found that the dye is protected by the spontaneous coiling of its attached low-viscosity oligomer.