Construction and ignition performance of microwave-responsive nAl@MOF composite energetic material

ABSTRACT Among the various stages of energy release in energetic materials, ignition is critical. Microwave ignition technology is an advanced method that converts microwave energy into thermal energy to achieve rapid ignition, offering advantages such as simple structure, non-contact operation, and excellent controllability. In this work, the nAl@MOF microwave absorber which differs from aluminum thermite was synthesized via hydrothermal methods. SEM and TEM analyses revealed its good morphology, confirming successful loading of nano aluminum particles into the MOF matrix. TG-DSC and in-situ infrared measurements demonstrated the material’s thermal stability up to 500 °C, enabling effective hot-spot generation during microwave ignition. Electromagnetic performance testing indicated that the constructed novel microwave absorber achieved an absorption efficiency of approximately 87.41% in the 2–18 GHz frequency range. A resonant cavity and microwave probe structure were designed for combined use, enabling efficient conversion of near-field electromagnetic energy into internal energy. This established a safe and controllable near-field microwave ignition device. Using this device, the nAl@MOF composite energetic material was ignited by microwaves. Results demonstrate that incorporating the microwave absorber reduced the microwave ignition delay time of the double base propellant from 503.6 ms to 77 ms. This work provides novel insights for developing microwave absorbers and composite energetic materials for microwave ignition, establishing a comprehensive evaluation methodology involving impedance matching, absorption intensity, and near-field microwave ignition studies.