Switching properties of fluorescent photochromic poly(methyl methacrylate) with spironaphthoxazine and D-π-A type pyran-based fluorescent dye.
Fluorescent photochromic poly(methyl methacrylate) (PMMA) with spironaphthoxazine (SPO) and D-π-A type pyran-base fluorescent dye as a fluorophore was synthesized by typical free radical copolymerization. The poly(MMA-co-SPO-co-fluorophore) in both solution and solid film exhibited excellent photoregulated fluorescence switching behavior and reversible modulation of fluorescence intensity using alternating irradiation with UV and visible light. The poly(MMA-co-SPO-co-fluorophore) also showed viscosity and conductivity switching behaviors along with photoresponse.
Effect of UV-irradiation on fluorescence of poly(methyl methacrylate) films with photosensitive organic compounds
Abstract The simple way of physical modification of poly(methyl methacrylate) (PMMA) for the purpose of formation its photoactivity and fluorescence properties has been described. It was found that aromatic carbonyl compounds (2,2-dimetoxy-2-phenylaceto-phenone, benzoyl peroxide and tert -butyl peroxybenzoate) dispersed in PMMA matrix changed its optical properties, which was studied by absorption and emission spectroscopy. Modified PMMA exhibits fluorescence upon excitation of 220 or 270 nm. The intensity of emission band decreases after samples exposure to short wavelength UV-irradiation, which is evidence of component photolysis. The fluorescence decay is slightly smaller for the irradiated initiators in PMMA matrix, but the trend is similar to that for pure initiators exposed to UV. The protective effect of PMMA on the studied compounds after UV-irradiation, however, is accompanied by photodegradation reactions occurring in the polymer, which was confirmed by viscometric measurements.
Another Photochromism of a Spironaphtoxazine Due to the Geometric isomerization of the Open-Form
The photodecoloration rate of colored spironaphtho[1,2-b]oxazine 2 was much slower than the corresponding [2,1-b]oxazine 1. Existence of another photochromic system between two of the open-form isomers of 2, in addition to the well-known one for 1 between the closed and the open forms, was proved.