Optical functions of substituted polyacetylene: Fluorescence image patterning and fluorescence thermosensor

The fluorescence quenching behavior of poly[l-(trimethylsilyl)phenyl-2- phenylacetylene] (PTMSDPA) in thin film was investigated for the purpose of application to (1) FL image patterning and (2) thermosensing. (1) When the film was exposed to 365-nm UV light with a power of 26 mW/cm² in air at room temperature, the fluorescence band with maximum at 530 nm rapidly decreased and then finely resolved fluorescent images were easily obtained using photomasks. After a prolonged irradiation time, the PTMSDPA film exhibited the IR absorption peaks due to carbonyl and hydroxyl groups. Based on this fact, we presumed that the fluorescence quenching was probably due to a small amount of peroxy radical formed initially on the UV irradiation. Moreover, the rule red-dispersed PTMSDPA film provided fluorescent images in multicolor by the irradiance of 1.7 mW/cm². (2) The fluorescence gradually decreased with increasing temperature while it definitely returned to the initial intensity after fully cooling. This change was also highly reversible on the repeating cycle.