Tunable multicolor afterglow including white light emission from poly(acrylic acid)-based room temperature phosphorescence materials via phosphorescence FRET

Room temperature phosphorescence (RTP) materials with multicolor afterglow emission have important application potential in multicolor display and anti-counterfeiting. However, the preparation of polymer-based multicolor RTP materials still faces challenges. In this work, we prepare a kind of ultralong RTP materials by facilely doping phthalimide (Pth) into poly (acrylic acid) (PAA) matrices based on the hydrogen-bonding interaction. Attributed to the wide phosphorescence emission band of PAA-Pth, the ternary doping systems are constructed by using PAA-Pth as donors and commercially available fluorescent dyes rhodamine B (RhB) or fluorescein (FL) as acceptors, which display multicolor afterglow from cyan to red and green through efficient phosphorescence Förster resonance energy transfer (FRET). More impressively, the quaternary doping systems PAA-Pth-RhB-FL with different molar ratios of FL exhibit tunable multicolor afterglow, including nearly white afterglow emission. Due to the different FRET efficiency of PAA-based multicolor RTP materials at different excitation wavelengths, they are successfully applied in color information encryption .