Bypassing Pre-Photoactivation in High-Barrier Polyamide for Robust and Scalable Organic Persistent Luminescence

Area of Science:

• Materials Science
• Polymer Chemistry
• Optoelectronics

Background:

• Organic persistent luminescent (OPL) polymers face a critical trade-off between ambient stability and barrier properties, limiting their use in demanding environments.
• Direct-doping systems exhibit humidity-induced degradation and slow excitation, hindering practical applications requiring rapid photoluminescence.

Purpose of the Study:

• To overcome the ambient stability limitations of OPL polymers.
• To develop OPL composites with enhanced moisture and oxygen barrier properties for stable, rapid-response luminescence.

Main Methods:

• Molecularly locking chromophores within a poly(m-xylene adipamide) (MXD6) matrix using melt doping.
• Engineering OPL composites leveraging MXD6's inherent barrier properties (OTR: 0.68 cm³·m⁻²·day⁻¹·bar⁻¹, WVTR: 5.3 g·m⁻²·day⁻¹).
• Utilizing integrated experimental and computational studies to understand the mechanism of stability.

Main Results:

• Achieved efficient multicolor afterglow with high quantum yields (Φafterglow = 30.6%) and long lifetimes (5.6 s) without pre-photoactivation.
• Demonstrated remarkable stability, retaining >90% afterglow efficiency after 30 days of continuous water immersion.
• Confirmed that disordered hydrogen bonding rigidifies the matrix and interlocks chromophores, creating a barrier for triple excitons.

Conclusions:

• The developed OPL composites offer a universal paradigm for ambient-stable OPL polymers, solving the stability-barrier trade-off.
• This strategy enables the creation of meter-scale fibers and transparent films, validating industrial viability for versatile luminescent devices.
• The OPL polymers are suitable for rapid-response luminescence in demanding environmental applications.