Photochromic Spiropyran-Based Dual-Emitting Luminescent Hybrid Films for Dynamic Information Anticounterfeiting

Area of Science:

• Materials Science
• Photochemistry
• Nanotechnology

Background:

• Photoluminescent materials are crucial for information storage and anticounterfeiting.
• Existing materials often lack dynamic capabilities and processability, posing challenges for high-security applications.

Purpose of the Study:

• To fabricate a novel photostimuli-responsive dual-emitting luminescent material for dynamic anticounterfeiting.
• To investigate the material's reversible luminescence switching and tunable color properties.

Main Methods:

• Sol-gel process to incorporate a photochromic spiropyran (SP) molecule and a terbium complex (Tb-hfa) into a siloxane-polyether matrix.
• Utilized photochromic fluorescence resonance energy transfer (FRET) for luminescence modulation.
• Investigated UV-light irradiation effects on luminescence.

Main Results:

• Successfully synthesized a dual-emitting material (UPTES-SP-Tb-hfa) exhibiting reversible luminescence switching.
• Demonstrated rapid, repeatable encryption/decryption (≥8 times) and dynamic color changes within 15 seconds.
• Achieved tunable luminescent colors using 254 nm and 365 nm UV light due to dual luminescent centers (Tb³⁺ and MC).

Conclusions:

• The developed material offers a novel approach for dynamic anticounterfeiting with enhanced security.
• The material's properties are suitable for creating advanced, multicolored anticounterfeiting labels.
• This work advances the design methodology for dynamic anticounterfeiting materials.