Titanium Nanoparticles on Reduced Boron Nanoparticles for Enhanced Combustion and Propulsion Performance in Hypersonic Fuel Systems

This study introduces a dual strategy combining oxide-layer reduction and physical mixing with ignition promoters to enhance the combustion performance of boron-based nanoadditive for scramjet engine fuels. Oxide-layer-reduced boron nanoparticles were functionalized with a silane layer to improve their dispersion stability in hydrocarbon fuels. To further accelerate ignition and exothermic reactivity, titanium nanoparticles (TNs) were physically integrated with silane-coated reduced boron nanoparticles (SRBNs), enabling a tunable composite system without altering the individual particle functionality. Compared with bare boron, the optimized SRBN–TN formulations exhibited significantly enhanced combustion characteristics, including shortened combustion time, higher peak temperatures, and increased calorific output. Thermal analysis and high-speed droplet combustion imaging confirmed that the synergistic effect of silane coating and TN-induced ignition promoted faster and more complete combustion with reduced soot formation. These findings highlight the advantage of integrating surface-functionalized boron with ignition-promoting metals as a practical and scalable approach for developing high-performance energetic nanoadditive in advanced propulsion systems.