Photo-Responsive Room-Temperature Phosphorescent Films Exhibiting Photochromism and Time-Dependent Phosphorescent...

Area of Science:

• Materials Science
• Photochemistry
• Polymer Chemistry

Background:

• Developing dynamic color-tunable room-temperature phosphorescence (RTP) materials with photochromism and time-dependent phosphorescence color (TDPC) is challenging for anti-counterfeiting.
• Existing methods often lack the required dynamic color-tuning and time-dependent properties.

Purpose of the Study:

• To demonstrate a facile in situ synthesis strategy for photo-responsive, color-tunable RTP polymer films.
• To achieve reversible photochromic and TDPC properties for advanced anti-counterfeiting applications.

Main Methods:

• In situ synthesis integrating carboxyl-functionalized spiropyran (SPCOOH) and a melamine (ME)-isophthalic acid (IPA) luminescent framework within a PVA matrix.
• Utilizing synergistic hydrogen-bonding networks to mediate material properties.
• Employing UV-induced spiropyran-to-merocyanine (SP→MC) isomerization and triplet-singlet Förster resonance energy transfer (TS-FRET).

Main Results:

• Achieved precise modulation of afterglow color from cyan to orange via TS-FRET between ME-IPA donor and MC acceptor.
• Demonstrated distinct decay kinetics due to energy transfer, imparting TDPC property.
• Successfully showcased multilevel time-resolved multicolor dynamic anti-counterfeiting applications.

Conclusions:

• Established a simple and effective strategy for constructing TDPC systems.
• Developed color-tunable RTP materials with reversible photochromic and TDPC properties.
• Paved the way for advanced dynamic anti-counterfeiting solutions.