Polymers Microspheres as Colorful Ultralong Organic Phosphorescence Delivery for Printable Optical Multiplexing

The development of ultralong organic phosphorescence (UOP) materials with programmable color is of great significance yet remains challenging for various optoelectronic applications. In this work, a novel type of polymer microspheres is presented as versatile carriers capable of regulating UOP colors through the reversible absorption and release of different phosphors. The rigid environment, facilitated by intermolecular hydrogen bonds between the aryl carboxylic acid groups of the phosphors and the crosslinked polyacrylamide (PAM) microspheres, effectively suppresses non-radiative transitions, enabling UOP with an impressive emission lifetime of 3.68 s. Specifically, these polymer microspheres serve as dynamic carriers that can reload and release uniformly dispersed phosphors in aqueous solution, thereby rearranging intermolecular hydrogen bonds and tuning the UOP emission color across a spectrum from blue to green and red. Furthermore, by incorporating fluorescent dyes into the polymer microspheres, the UOP color range can be extended to cover the entire visible spectrum through energy transfer mechanisms. Finally, the successful application of these UOP polymer microspheres is demonstrated in optical multiplexing. This study not only proposes a novel strategy for achieving color-tunable UOP in polymer microspheres but also broadens their potential applications in advanced optoelectronic technologies.