Camera Method for Monitoring a Mechanochromic Luminescent β-Diketone Dye with Rapid Recovery

Area of Science:

• Materials Science
• Photophysics
• Organic Electronics

Background:

• Mechanochromic luminescent (ML) materials offer dynamic optical responses to mechanical stimuli.
• Applications include sensors, optical memory, and advanced lighting.
• Few ML materials exhibit efficient room-temperature self-erasing capabilities.

Purpose of the Study:

• Investigate the room-temperature self-erasing properties of methoxy-substituted β-diketone gbmOMe.
• Characterize the decay dynamics of the mechanically induced state.
• Evaluate the influence of substrate and film thickness on ML recovery.

Main Methods:

• Fabrication of gbmOMe thin films on various substrates.
• Mechanical smearing to induce mechanochromism.
• Complementary metal-oxide-semiconductor (CMOS) camera imaging for emission analysis.
• Differential scanning calorimetry (DSC) for thermal analysis.

Main Results:

• GbmOMe thin films exhibited a reversible color change from blue to green emission upon mechanical smearing.
• A novel CMOS camera method enabled characterization of the rapid smeared-state decay (τ_SM).
• ML recovery was largely substrate-independent but significantly influenced by film thickness.
• Melted gbmOMe thin films formed a stable amorphous (supercooled liquid) state, unlike bulk powders.

Conclusions:

• GbmOMe demonstrates promising room-temperature self-erasing mechanochromic properties.
• Film thickness is a critical parameter for controlling ML recovery dynamics.
• The amorphous state in thin films offers potential for stable, responsive materials.