Preparation and Modulation of Temperature-Responsive Multicolor Phosphorescent Materials

Abstract

Organic room-temperature phosphorescent (RTP) materials hold great promise for environmental sensing, yet their poor structural stability, moisture-induced quenching and non-tunable afterglow color limit their wide applications. To solve these issues, a long-lived RTP material 14PA@HPD was synthesized via dehydration condensation of 1,4-phenylenebisboronic acid (14PA) and 2-(hydroxymethyl)-1,3propanediol (HPD), and exhibited an ultralong phosphorescence of 2.27 s lifetime and temperature responsive behavior (red-shift from 430 to 500 nm at the range of 77 K to 298 K). 14PA@HPD (10 wt%) was doped into a poly (methyl methacrylate) (PMMA) matrix to fabricate composite films. These films showed phosphorescence lifetimes of 1.52 s at 465 nm and 1.78 s at 500 nm, and the lifetime remained above 0.5 s after 40 min of water immersion. Interestingly, by doping several suitable fluorescent dyes as energy acceptors, multicolor long-afterglow composite films ranging from blue-green to yellow were obtained, affording delayed fluorescence of 0.12 s at 570 nm. These tunable afterglow materials showed excellent processability and were applied in fluorescence-phosphorescence dual-mode anti-counterfeiting and cryogenic pipeline leakage warning, providing a new strategy for multifunctional RTP materials.