Mechanochemically Induced Circularly Polarized Luminescence from Polymers

Area of Science:

• Polymer Chemistry
• Materials Science
• Optics

Background:

• Achieving diverse optical signals, especially polarized light, in polymer mechanochemistry is difficult.
• Mechanochemically induced circularly polarized luminescence (MICPL) offers a novel approach to control light polarization through mechanical stimuli.

Purpose of the Study:

• To pioneer the development of MICPL in polymers.
• To design and synthesize crosslinked polymer networks capable of emitting CPL upon mechanical compression.
• To explore the tunability of CPL properties by varying mechanophores and polymer matrices.

Main Methods:

• Photopolymerization of achiral mechanophores with a chiral monomer (L(-)-bornyl acrylate, LBA).
• Mechanical compression to trigger retro-Diels-Alder reactions, releasing fluorophores.
• Analysis of force-dependent CPL emission and luminescence dissymmetry factor (g_lum).

Main Results:

• Successful creation of polymers exhibiting bright, force-dependent CPL.
• Achieved high luminescence dissymmetry factors (up to 10^-2).
• Demonstrated tunable CPL colors (blue-violet to yellow-orange) and white CPL emission through system variation.

Conclusions:

• Developed a versatile strategy for on-demand CPL materials using polymer mechanochemistry.
• Established a platform for macromolecular chiral optical probes for multimodal stress reporting.
• Resolved fundamental questions regarding mechanical force-regulated chirality in polymers.