Why and how type of passivation layer affects the properties of aluminum nanopowders for energetic applications

Results of DTA-TG-investigations and chemical analysis of electro-exploded aluminum nanopowders, coated and/or passivated by the reactive reagents: nitrocellulose (NC), ethanol, Teflon, oleic (C17H33COOH) and stearic (C17H35COOH) acid, amorphous boron, nickel, air, and ALEX (for comparison) are shown. The disadvantages of aluminum nanopowders, passivated by air and covered by a thick oxide layer, which affects adversely their energetic properties, are their low metal content and their low stability to further oxidation during storage. Non-oxide coatings, i.e., aluminum nanopowders with a protecting surface are expected to have improved material properties. The kinetics of the interaction of aluminum nanopowders with nitrogen, air, and in water are described.