Ultralong Room‐Temperature Phosphorescent Coatings Enabled by Coronene Aggregates in Specialty Epoxy Resin: Wide‐Range Excitation From Violet to Green Light

Why It Matters

The breakthrough expands RTP use to low‑energy green lighting and high‑temperature environments, unlocking new possibilities for secure data encryption, anti‑counterfeiting and durable luminescent coatings.

Key Takeaways

• UV‑induced coronene aggregates enable green‑light excitation
• Phosphorescence lifetime reaches 6.2 s, afterglow up to 90 s
• Afterglow persists at 135 °C thanks to high‑Tg epoxy
• Simple painting process eliminates need for hot‑pressing

Pulse Analysis

Room‑temperature phosphorescent (RTP) materials have long been prized for their ability to store light energy and release it as a prolonged afterglow, a feature valuable for security printing and information storage. Historically, most RTP systems required ultraviolet excitation or suffered from short lifetimes, limiting practical deployment. By leveraging UV‑induced coronene aggregates within a high‑glass‑transition epoxy matrix, the new coating overcomes these hurdles, delivering efficient excitation with ordinary violet, blue, white or even green LEDs—a wavelength range compatible with everyday lighting infrastructure.

Performance metrics set this technology apart. Under violet or blue illumination, the coating achieves a phosphorescence lifetime of 6.2 seconds and an afterglow that can linger for up to 90 seconds, dwarfing the previous 40‑second benchmark for coronene‑doped polymers. Green‑light excitation, previously unattainable for RTP, yields a respectable 12‑second afterglow, while phosphorescence resonance energy transfer extends red afterglow to 60 seconds. Crucially, the epoxy’s high glass transition temperature preserves luminescence at 135 °C, opening doors to high‑heat industrial environments where conventional RTP materials would fail.

The commercial implications are significant. A paint‑on application eliminates costly hot‑pressing steps, enabling rapid retrofitting of existing surfaces with luminescent security layers. Industries ranging from anti‑counterfeit packaging to aerospace component tracking can benefit from a coating that is both temperature‑resilient and excitable by low‑cost LEDs. As the market for secure, smart coatings expands, this coronene‑based RTP system positions itself as a scalable, cost‑effective solution, likely spurring further research into aggregate‑driven phosphorescence and broader adoption across high‑value supply chains.