Microwave-Activatable Heterointerfaces With B/N-Regulated Carbon Nitride Bridge for Coupling Microwave Absorption,...

Microwave-programmable energetic materials (EMs) offer opportunities for remotely controllable ignition and energy-release systems, yet inefficient microwave-activatable interfaces limit the electromagnetic energy conversion in EMs. Herein, we report an atomic-network strategy to transform microwave-insensitive cyclotetramethylenetetranitramine (HMX) into a microwave-responsive supramolecular aerogel. Boron- and nitrogen-regulated carbon nitride (BCN) was designed as a multifunctional "interfacial bridge" to assemble HMX with metastable intermolecular composite (MIC) sensitizers, constructing an activatable HMX-BCN-MIC heterointerface. B/N-regulated heptazine framework reinforces dielectric polarization, charge transport, and hydrogen-bonding interactions through defect-rich grain boundaries, conductive microchannels, and abundant cyanogroup (─C≡N) sites. BCN exhibits a 45% increase in apparent carrier density, a 20.3% decrease in charge-transfer resistance, and a 10.3% increase in dielectric loss (ε″) compared with pristine CN. Meanwhile, BCN-mediated heterointerfaces reduce the activation energy of rate-determining step in HMX decomposition by 22.8% through active B-doped sites and multiple NO_x conversion pathways. The reinforced hydrogen‑bonding network further stabilizes the HMX‑BCN‑MIC heterointerface, which serves as an electron pump for the rapid conversion from electromagnetic energy to thermal energy. The optimized HMX-based aerogel can achieve a rapid microwave response speed (82.3 ms) and enhanced flame output. This work provides a design paradigm for developing microwave-programmable EMs.