Spectral and Acoustic Characterization of Nanoenergetic Devices Based on Sodium Perchlorate-Impregnated Porous Silicon

This work reports the controlled synthesis and characterization of nanoenergetic composites composed of porous silicon (PS) impregnated with sodium perchlorate (NaClO₄) for precision energy-release applications. PS films were fabricated by electrochemical anodization of p-type silicon (10-20 Ω·cm), with systematic variation in current density (50-200 mA cm^-2) and anodization time (10-25 min) to tailor pore morphology. The energetic behavior of the composites was evaluated through thermal ignition tests, optical emission spectroscopy (300-1000 nm), acoustic analysis (0-500 Hz), and high-speed imaging. Optimal energy release was obtained for PS films anodized at 100 mA cm^-2 for 15-20 min, attributed to their hierarchical pore architecture that facilitated complete oxidant infiltration. Overall, this work provides additional insights beyond previous reports by correlating the explosive efficiency with both anodization time-linked to PS film thickness-and current density-associated with porosity. A portable multispectral optical system with fiber-optic access to the explosion chamber was developed for in situ characterization, offering a safe and versatile approach for measurements in explosive environments. To the best of our knowledge, no prior studies have analyzed the correlation between the acoustic signatures and explosion intensity in PS-NaClO₄ systems as proposed here.