Cycloolefin Copolymers With a Multiply Rigid Structure for Protecting Triplet Exciton From Thermo‐ and Moisture‐Quenching

Abstract Polymeric room temperature phosphorescence (RTP) materials have been well developed and utilized in various fields. However, their fast thermo‐ and moisture‐quenching behavior highly limit their applications in certain harsh environments. Therefore, the preparation of materials with thermo‐ and moisture‐resistant phosphorescence is greatly attractive. Compared with common water‐soluble polymers, cycloolefin copolymers (COC) show outstanding hydrophobicity and higher rigidity, even at elevated temperatures, being as a promising candidate to prepare phosphorescence materials with suppressed thermo‐ and moisture‐quenching behavior. Herein, a type of COC bearing hydroxyl, ester, and adamantanyl side groups is synthesized. After dispersing various phosphors into this matrix, the resultant composites exhibit full‐color RTP with lifetimes of 249–590 ms. Their luminescence does not show obvious quenching in water, acid, alkalinous, reductive, and oxidative environments. In the presence of both rigid COC matrix and rigid phosphors, the corresponding composite displays high‐temperature phosphorescence performance. Even at 378 K, the composite can emit phosphorescence with a lifetime of 40–98 ms. The applications of these COC‐based composites for imaging, information encryption, and anti‐counterfeiting are thus explored.