Realizing the hygroscopicity suppression and laser responsiveness of ADN via surface coating with hydrophobic conductive polymer

Ammonium dinitramide (ADN) has emerged as a next-generation oxidizer for solid propellants owing to its exceptional energy density, low characteristic signal and environmental friendliness. Nevertheless, its pronounced hygroscopic poses significant challenges for practical implementation. To address this critical limitation, we developed ADN@PFN composites by solvent evaporation, in which hydrophobic and conductive polymer polyfluorene (PFN) was coated on the ADN surface. When the coating amount of PFN is 5 wt %, the water contact angle of the ADN@PFN composites was increased to 124.4° from 0° (untreated one) and the hygroscopicity was reduced by 90 % (25 °C, 65 % RH). The thermal stability of ADN@PFN composites was improved with the decomposition temperature increasing around 10 °C. The impact and friction sensitivities of ADN@PFN composites were 21 J and 240 N, respectively, which are both better than those of untreated ADN (IS:10 J FS: 96 N). Notably, the ADN@PFN composites also realized laser ignition due to good light absorption efficiency of PFN. This multifunctional modification strategy not only overcomes the intrinsic hygroscopicity limitation of ADN but also enables ADN with increased thermal stability and mechanical safety, as well as laser responsiveness.