The Burning Rate of Energetic Films of Nanostructured Porous Silicon

A systematic study of nanoenergetic films consisting of nanostructured porous silicon impregnated with sodium perchlorate is carried out. The explosive properties of these films are investigated as a function of thickness, porosity, and confinement. The films' burning rates are investigated using fiber-optic velocity probes, demonstrating that flame-front velocities vary between approximately 1 and 500 m s^-1 and are very sensitive to the films' structural characteristics. Analysis of the flame profile by high-speed video is also presented, suggesting that the reaction type is a deflagration rather than a detonation. A strong plume of flame is emitted from the surface, indicating the potential for this material to perform useful work either as an initiator or as a propellant. The shape of the flame front transitioned from an inverted V at thin-film thicknesses to a neat square-shaped front once the material became self-confining at 50 μm. Porous silicon impregnated with sodium perchlorate reacts explosively when initiated by a high voltage spark. The burning rate of this energetic material is investigated using fiber-optic velocity probes and high-speed video, demonstrating velocities up to 500 m s^-1. Strong plumes of flame emerge from the surface, leading to applications in micro-electromechanical systems.