Dynamic Reversible Full-Color Phosphorescence Afterglows from Stimuli-Responsive Carboxymethyl Chitosan Based...

Area of Science:

• Materials Science
• Organic Chemistry
• Polymer Science

Background:

• Organic stimuli-responsive persistent room-temperature phosphorescence (p-RTP) materials are crucial for applications like encryption, bioimaging, and sensing.
• Developing efficient p-RTP systems with full-color tunability and multi-dimensional responsiveness, especially from nonconventional luminophores, is a significant challenge.

Purpose of the Study:

• To develop a novel, efficient, and stimuli-responsive p-RTP system using nonconventional luminophores.
• To achieve full-color tunability and multi-dimensional reversible responsiveness in p-RTP materials.

Main Methods:

• Investigated marine-derived carboxymethyl chitosan (CMCS) for intrinsic photoluminescence (PL) and p-RTP properties.
• Constructed a pyrenedicarboxylic acid salt-doped phosphorescence system utilizing CMCS.
• Evaluated p-RTP characteristics including quantum yield, emission duration, and tunability via pH, delay time, and excitation wavelength.

Main Results:

• CMCS demonstrated intrinsic excitation-tunable panchromatic PL (400-610 nm) and a record p-RTP quantum yield (10.1%) for nonconventional polymers.
• The doped system exhibited efficient (8.8%), prolonged (515.1 ms), and dynamically tunable p-RTP (495-710 nm).
• Achieved cyclable control of p-RTP through pH, delay time, and excitation wavelength, demonstrating multimode stimuli-responsiveness.

Conclusions:

• Achieved efficient, multi-stimuli-responsive p-RTP by combining nonaromatic CMCS with aromatic chromophores, controlling molecular interactions and aggregation.
• This approach overcomes limitations of conventional aromatic modification strategies for p-RTP development.
• The developed system shows potential for versatile applications in anti-counterfeiting, encryption, information storage, and phosphorescent textiles.