| 초록 |
The colored merocyanine form of the spiropyrans is unstable and the relaxation back to the initial colorless state often occurs spontaneously even in the dark at room temperature. One of the strategies to improve stability of the merocyanine form is the acid treatment on the spiropyrans under irradiation of UV light. Such treatment produced a salt form between the photomerocyanine and the acid, and the resulting colored species was quite stable. If the acid treatment on the films containing spiropyrans is carried out in the selected areas, then stable patterned images accompanying change of color and fluorescence will be produced. Moreover, refractive index modulation would be also possible in the selective region through the method. In this work, we introduced a novel approach to developing color and fluorescence imaging and refractive index modulation by photo-irradiation on the polymer films containing a photochromic spiropyran derivative and a photoacid generator. When the films were exposed to UV light through a mask to make a patterned image, the fine yellow lines were resolved in a range of 12 to 50 μm. The refractive index change by the UV-irradiated films was determined by a prism coupler method as 0.0022, 0.0027, and 0.0048 with a 5, 10, and 40 wt % content of SP1 in the PMMA films, respectively. |
