Design, Preparation And Application Of Multi-Responsive Fluorescent Monomers And Fluorescent Compositions

Functional fluorescent monomer can achieve multiple response characteristics to a variety of external stimuli through molecular design (such as ultraviolet light, heat treatment, mechanical disturbance, pH changes, etc.).Compositions formulated from such fluorescent monomers can be fluorescently labeled on different substrates by spraying or otherwise. Therefore, the multi-response fluorescent monomer and its composition are stimulated by different external stimuli, and the coloration or fluorescence is changed, which has important application prospect in information recording, storage, marking and anti-counterfeiting.In this paper, six kinds of spiropyran derivatives were designed and synthesized. The photochemical properties of these six compounds were investigated by UV spectrophotometer and fluorescence spectrophotometer. On the basis of these researches, the fluorescent monomer SPODA, which is sensitive to dual-band UV response, temperature response and pH, was designed and synthesized, and the corresponding fluorescent composition was prepared. The multi-response properties of the fluorescent monomer and the fluorescent composition were analyzed by UV-Vis spectroscopy and fluorescence spectroscopy. The main research contents are as follows:First, six spiropyran derivatives were designed and synthesized.Diacetylene was introduced into benzopyran and indole rings of spiropyran compound, and flexible chains and rigid molecules of different lengths (Pc3, Hc6,and Oc8) were attached to the indole ring. The effects of diacetylene access position, flexible groups and rigid groups on the photochemical properties of the compounds were investigated, which provides a theoretical basis for the preparation of fluorescent monomers with multi-response characteristics.Second, the fluorescent monomer 8-bromo-l -octanol-N-hydroxyethyl-3,3-dimethyl-6'-nitroindoline spiropyranyl ester (SPODA) was designed and synthesized, which is sensitivity to dual-band ultraviolet light, heat treatment and pH changes. The experimental results show that the synthesized fluorescent monomer SPODA can respond to different wavelengths of ultraviolet light, heat treatment and acid-alkali treatment.Third, a fluorescent composition containing the fluorescent monomer SPODA was prepared, which can respond differently of dual band UV light, the temperature and acid-alkali. The patterns on different substrates become a variety of colors after being stimulated. The results provide an important theoretical basis for the development of new fluorescent inks with multiple response characteristics.