Aluminum is a highly reactive metal, and its nanoparticle form is especially active. As a result, it has been widely used in energetic material formulations to improve their performance by increasing reaction energies and blast rates.
Aluminum nanoparticles are also attracting interest for use in medical and cosmetic applications because of their unique mechanical properties, including low density and high strength. These properties can be enhanced further by incorporating other elements and functionalities into the nanoparticles to achieve a desired property.
Laser-based synthesis of aluminum nanoparticles has been shown to be effective for this purpose. The resulting spherical aluminum nanoparticles were found to stimulate flow-dependent platelet microaggregation in vitro, as demonstrated by QCM-D. Additionally, the nanoparticles were able to stabilize blood under shear conditions and suppress cell proliferation.
The authors developed a method for producing nanoparticle aluminum that is compatible with laser additive manufacturing (LAM). The resulting powders were capable of being directly layer-deposited on TiCN substrates using laser-based energy deposition, achieving an excellent AMNC specimen with a Young’s modulus close to that of pure aluminum. The aqueous stability of the nanoparticles was improved by passivating them with organic polymers, metal-organic frameworks or other metal oxide shells. Unpassivated aluminum nanoparticles will oxidize rapidly in water.
The authors also report on the characterization of the aluminum nanoparticles using a variety of techniques, including thermogravimetric analysis, X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption isotherms. The authors developed a facile method for producing these aluminum powders on a hundred-gram scale, using ammonium chloride and aluminum(III) acetylacetonate as grinding aid and surface passivation agents.