Schiff-Base porous film for NO2 detection to Enable monitoring of solid propellant aging

In this study, an organic molecular probe containing an imine (C=N) linkage was synthesized and embedded in a polymethylmethacrylate (PMMA)/polyethylene glycol (PEG) matrix to fabricate a porous optical film for NO 2 gas detection via solid-state UV spectroscopy. Upon exposure to NO 2 , the film exhibited significant spectral changes, with a detection limit as low as 26.45 ppm. Mechanistic investigations revealed that NO 2 induced non-covalent interactions with the probe, triggering structural reorganization and enhanced π-conjugation. Density Functional Theory (DFT) calculations further supported these findings by confirming changes in electronic structure and energy levels. Additionally, preliminary tests demonstrated the feasibility of applying this probe film for aging detection of NEPE propellants, offering a promising non-destructive approach for monitoring propellant health.