Preparation of Tunable Multicolor Persistent Room Temperature Phosphorescence Materials by Doping Cellulose Nanocrystals with Aromatic Carboxylic Acids

Abstract Persistent organic room temperature phosphorescence (p‐RTP) luminescent materials have broad application prospects in multiple anti‐counterfeiting encryption and other fields. It is generally difficult for single component substances to achieve adjustable full color gamut p‐RTP afterglow, and dual component doping may be a feasible solution. Here, by doping a small amount of aromatic acid molecules with controllable conjugation into cellulose nanocrystals (CNC), which can generate various interactions, and full color gamut long afterglow emitting luminescent material with blue to red light is successfully prepared under the same excitation. Not only does it achieve adjustable afterglow color, but it also has long afterglow emission (447.02 ms). The high crystallinity of CNC and its strong hydrogen bonding with doped molecules endow aromatic acid molecules with a liquid nitrogen like environment, resulting in a multi‐color afterglow under strong conformational hardening. The frontline orbit theory calculation also proves the above speculation. This simple method for preparing powder materials with all color gamut adjustable p‐RTP emission has proven to have great commercial prospects in the field of multiple anti‐counterfeiting encryption.