Structure‐Engineered Mesoporous AlSi/P(VDF‐HFP) Energetic Composites with Diffusion‐Enhanced Reactivity

ABSTRACT Aluminum (Al)‐based alloys have emerged as promising solid fuels for energetic composites (ECs) owing to their multi‐metallic properties. However, their energy release efficiency is severely limited by diffusion‐controlled reaction kinetics. In this work, a novel functionalized mesoporous AlSi alloy fuel is designed via a sequential etching and fluorination strategy and combined with P(VDF‐HFP) to form AlSi/P(VDF‐HFP) ECs. This structure‐engineered design effectively overcomes the kinetic constraints imposed by sluggish diffusion. The mesoporous Si framework catalyzes the decomposition of P(VDF‐HFP) and provides abundant channels for gas transport. Moreover, the dissociation and recombination of F ⁻ on the fluorinated surface are analyzed by XPS, and molecular dynamics calculation shows a stronger binding capability between grafted fluorinated chains and P(VDF‐HFP) through intensive C─F···F─C and C─F···H─C interactions. Remarkably, the optimized ECs exhibit a significant increase in reaction heat compared to the pristine composites, accompanied by a reduction in activation energy. Ignition and closed‐bomb tests further demonstrate substantially enhanced combustion performance and pressurization capability. Based on experimental evidence, a reaction mechanism is proposed. This work provides an accessible pathway for improving the reactivity of alloy‐based ECs.