• • Achieved maximum phosphorescence lifetime (τPhos) of 1754 ms and quantum yield (ΦPhos) of 42.83% in PM0.1-0.01-1 microspheres, outperforming prior intrinsic polymer RTP materials and enabling high-efficiency afterglow applications.
• • At 77 K, microspheres exhibit ultralong green emission with lifetime of 6019 ms and visible afterglow up to 99 s, suitable for cryogenic temperature sensing and security marking.
• • Thermo-responsive behavior demonstrated across 20–100 °C in aqueous solution for PMx-1-0.01 series, with distinct spectral shifts and intensity variations, enabling temperature sensing with high thermal sensitivity.
• • Cross-linked microspheres maintain phosphorescence stability in aqueous and high-temperature environments, supporting robust operation in practical conditions for information encryption and LED applications.