Polymerization‐Induced Emission of Color‐Tunable Room Temperature Phosphorescence

Abstract Pure organic room‐temperature phosphorescence (RTP) materials have been widely utilized in security signs, anti‐counterfeiting, data encrypting, and other fields, which have attracted great attention. In the past few years, smart materials with color‐tunable organic RTP materials are reported by many researchers, while the work focused on the color‐tunable polymeric RTP materials is still rare, especially for molecular weight‐dependent polymeric RTP systems. Here, we designed and prepared three molecular weight polymers P1, P2, and P3 by different polymerization reaction times, and found that the fluorescence emissions of these polymer powders are various. Unexpectedly, the molecular weight‐dependent polymeric RTP materials are achieved through doping these polymers into polyacrylonitrile (PAN) matrix, and the International de l'Eclairage was redshift from (0.205,0.257) to (0.503,0.435). This phenomenon is ascribed to the different aggregation states formed by assembly of different molecular weight polymeric chains. Meanwhile, the electrostatic interaction between phosphor and PAN is hardly affected by water. Therefore, advanced information encryption can be achieved by using these polymeric phosphors as anti‐counterfeiting ink.