Ionic Oligomer-Mediated High-Concentration Dissolution of Inorganic Ammonium Perchlorate in Organic Solvents for Controllable Fabrication of Ultrafine Particles with Enhanced Energetic Performance

Small-sized ammonium perchlorate (AP) particles can significantly improve the burning rate and energy density of solid propellants. However, the development of ultrafine AP (UFAP) particles with controlled morphology remains a critical challenge due to the inherently low solubility of inorganic salts in organic solvents and the safety risks associated with conventional refinement methods. Herein, a strategy mediated by ionic oligomers is proposed to achieve a high-concentration dissolution of AP in methanol (MeOH)/triethylamine (TEA) mixed solvents via hydrogen bonding and van der Waals interactions. The results show that this ionic oligomer-mediated dissolution enables a substantially higher AP concentration in organic media than conventional single-solvent dissolution approaches. Leveraging this solvent system, UFAP has been successfully fabricated through antisolvent recrystallization, with precise control over particle size (2.5∼4.0 μm) and morphology (tetrahedral) by optimizing surfactant selection (isostearic acid), antisolvent type (isooctane), and stirring rate (800 rpm). The resulting UFAP exhibits significantly improved thermal decomposition performance, with the low- and high-temperature decomposition peak temperatures reduced by 8.5 and 35.8 °C, respectively, compared to raw AP. Furthermore, solid propellants incorporating UFAP demonstrate a 43.5% increase in burning rate and a combustion temperature exceeding 2068 °C under 5 MPa, attributed to enhanced surface reactivity and mesoporous structures facilitating rapid heat transfer. This work provides a universal solvent design framework for high-concentration dissolution of inorganic salts in organic media, establishing a scalable and safe way for the fabrication of ultrafine energetic materials for application in next-generation high-performance propellants.