Phase-transition-induced phosphorescence: A novel icing detection strategy for airplane

Icing has been proven to be one of the main factors causing aviation accidents. Therefore, the development of convenient and intelligent icing detection technology for airplanes in high-cold areas before takeoff is of great significance to ensure its flight safety. Herein, a novel B-based phosphorescent material (h-PA/BA) was simply fabricated by heat treatment of boric acid (BA) and phenylboric acid (PA) precursors. The obtained h-PA/BA emits blue fluorescence (FL) and green phosphorescence (PL) with an observable time for 15 s (PL lifetime 1.203 s). More interestingly, the h-PA/BA can be dispersed well in aqueous solution with quenched PL, but a stronger PL can then be regenerated due to the phase transition from solution to solid (icing) by inhibiting the non-radiative process. The mechanism of PL generation-quenching-recovery for h-PA/BA under different states is studied in detail. By introducing h-PA/BA into commercial deicing liquid (DL), the novel DL developed with an ice warning function (i-DL) can successfully determine whether the airplane is icing according to the changes in FL and PL. This work opens the door to developing novel specific PL materials, which can expand their applications in airplane safety based on the phase-transition-induced phosphorescence during icing.