Synthesis of fluorenyl-based poly(aryl ether) and preparation of fluorescent fiber membrane for silica dust early warning response

Silica (SiO2) dust pollution not only causes respiratory diseases but also poses a threat to the safety of electronic manufacturing and chemical production. Therefore, utilizing the fluorescence properties of materials to monitor SiO2 for achieving early warning functions has great significance. In this work, a series of fluorenyl-based poly(aryl ether)s with excellent solubility, thermal stability and optical properties was synthesized via the Friedel-Crafts reaction. Furthermore, the solvent ratios were investigated to obtain electrospun fiber membranes with uniform morphology and optimal luminescence performance. The results showed that the fiber surfaces were smooth, with an average diameter of 3.5 μm, when the volume ratio of chloroform (CHCl3) to N-methylpyrrolidone (NMP) was 8:2. The fiber membrane exhibited strong blue fluorescence. In addition, the fluorescence stability test indicated that the fluorescence intensity retention rate of the optimal fiber membrane was 92% under acidic conditions. The fluorescence intensity of the sample remained at 98% under relative humidity conditions ranging from 20% to 70%. SiO2 nanoparticles caused a notable fluorescence quenching effect on the sample membrane. When the concentration of SiO2 in the air reached 0.05 mg/m³, the fluorescence intensity of the fiber membrane decreased by 45%. The highly sensitivity fluorescence response to SiO2 provides an intelligent method for dust monitoring in the future.