A “Micro-vision” of the Physio-Chemical Phenomena Occurring in Nanoparticles of Aluminum

From Prompt Gamma neutron Activation Analysis (PGAA) of nanoparticles of aluminum, impurities of boron, hydrogen, and water were detected in the material. The morphology of the nanoparticles was examined by atomic force microscopy and high-resolution transmission electron microscopy. The smallest (<10–20 nm) particles were found to be crystallographic in shape, becoming very spherical for larger particle sizes. X-ray diffraction data have evidenced a pristine aluminum crystal lattice, with no residual strain and an amorphous alumina or aluminum hydroxide surface, which is typically about 2.5 nm in thickness. PGAA data revealed that 2 times more water, from absorbed humidity, resided on the nanoaluminum surface as compared with standard “flaked” aluminum. This is providing evidence for the fact that the outer oxide surface in the nanoaluminum appears to have a higher porosity than in the standard “flaked” material. Finally, electrostatic charge detected on the nanoaluminum is reported and linked with potential “dust explosions” to which the nanoaluminum material might be more susceptible.