Multi-component crosslinking for humidity-resistant room temperature phosphorescence

Embedding organic chromophores into a polyvinyl alcohol (PVA) matrix has been proven to be an effective approach for producing various room temperature phosphorescence (RTP) materials under ambient conditions. However, due to the hydrophilicity of PVA, these RTP materials typically experience significant quenching of phosphorescence in the presence of moisture. Herein, we present a general strategy for achieving humidity-resistant RTP based on the PVA matrix by enhancing the hydrophobicity of PVA films through a multi-component crosslinking reaction. Our experiments demonstrate that the cross-linked PVA films simultaneously exhibit notable humidity resistance and an extended phosphorescence lifetime of 3.18 s under high humidity conditions. Furthermore, owing to the humidity-resistant properties of the PVA film, we highlight potential applications in information anti-counterfeiting and data encryption. This strategy offers a new route for developing humidity-resistant PVA films with ultralong organic phosphorescence at room temperature. • This work presented a facile strategy to obtain the humidity-resistant RTP. • Crosslinking can improve the efficiency and lifetime of the phosphorescence. • The restriction of molecular motion by covalent bond is the main reason. • The humidity-resistant RTP expands the application in encryption.