Achieving Highly Robust Polymeric Microspheres with Efficient and Full-Color Organic Afterglow for 3D Printing and...

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Developing luminescent materials with efficient and stable organic afterglow is crucial for advanced applications.
• Polymer-based luminescent microspheres offer advantages in processability and robustness.
• Existing organic afterglow materials often suffer from poor stability and limited color tunability.

Purpose of the Study:

• To develop highly robust polymer-based luminescent microspheres with efficient and full-color organic afterglow.
• To investigate the incorporation of guest luminogens into polymer matrices for tunable afterglow properties.
• To demonstrate the potential applications of these novel luminescent microspheres.

Main Methods:

• Host-guest doping and emulsion polymerization were used to embed guest luminogens (N-phenylnaphthalen-1-amine, N-phenylphenanthren-9-amine, N-phenyltriphenylen-2-amine) into melamine-formaldehyde polymer matrices.
• Characterization of the resulting polymer microspheres (≈2 µm diameter) for their luminescent properties, including afterglow color, phosphorescence quantum yields, and lifetimes.
• Exploration of dual-mode organic afterglow and persistent fluorescence by modifying guest luminogens and utilizing phosphorescence resonance energy transfer (PFER).

Main Results:

• Polymer microspheres exhibited blue to yellow-green organic afterglow at room temperature with high phosphorescence quantum yields (up to 18.0%) and long lifetimes (up to 1.39 s).
• Dual-mode organic afterglow and persistent red fluorescence were achieved with a lifetime of 0.24 s and a quantum yield of 22.2%.
• The developed microspheres demonstrated outstanding resistance to water and organic solvents, highlighting their robustness.

Conclusions:

• A universal strategy for creating efficient, robust, and colorful polymer-based organic afterglow microspheres has been established.
• These microspheres show significant potential for applications in stretchable elastomers, information anti-counterfeiting, 3D printing, and explosive detection.
• The developed materials represent a breakthrough in comprehensive organic afterglow performance for polymer-based luminescent microspheres.