Boron Based Bi2O3/PVDF Nano-Energetic Composite Films

Abstract Boron (B)-based energetic materials are promising for micro-electro-mechanical systems (MEMS) and multifunctional energetic devices because of their high gravimetric heat and volumetric energy density. However, a dense surface boron oxide (B2O3) passivation layer hinders ignition and limits energy-release efficiency. During pyrolysis, poly(vinylidene fluoride) (PVDF) generates fluorinated species that remove this layer and trigger a pre-ignition reaction, while bismuth(III) oxide (Bi2O3) acts as an oxidizer to enhance reaction and heat release. Here, boron-based Bi2O3/PVDF nano-energetic composite films were prepared by ball milling combined with electrospinning, achieving nanoscale dispersion and interfacial coupling. Under a fixed (B/Bi2O3):PVDF mass ratio of 30:70, samples with different B/Bi2O3 ratios (100:5, 100:10, 100:15, and 100:20) were prepared. All films exhibited excellent hydrophobicity. The films with B/Bi2O3 ratios of 100:10−100:15 demonstrated an optimal balance between structural integrity and energetic reactivity. It also showed that no formation of crystalline phases or chemical bonds, indicating that the ternary system is dominated by physical mixing and weak interfacial interactions. Notably, the sample containing 15% Bi2O3 exhibited the strongest catalytic effect, reducing the initial oxidation temperature by 173.96 °C compared with the raw boron. Its combustion duration shortened from 3.1 to 2.2 s, and combustion temperature reached 1533 °C. Overall, the ternary system regulates ignition and energy release through fluorination-assisted and interface-enhanced oxidation, offering a strategy for efficient multicomponent boron-based energetic films.