Afrl-rx-wp-tp-2011-4288 Influencing Solvent Miscibility and Aqueous Stability of Oxide Passivated Aluminum Nanoparticles through Surface Functionalization with Acrylic Monomers (preprint)

With increasing interest in the development of new composite systems for a variety of applications which require easily processible materials and adequate structural properties with high energy densities, we have pursued the chemical functionalization of oxide passivated aluminum nanoparticles (nAl) using three acrylic monomers, 3‐(trimethoxysilyl)propyl methacrylate (MPS), 2‐carboxyethyl acrylate (CEA) and phosphoric acid 2‐hydroxyethyl methacrylate ester (PAM), to provide chemical compatibility within various solvent and polymeric systems. FTIR and XPS suggest that attachment of MPS and PAM monomers occurs through the formation of bonds directly to the passivated oxide surface upon reaction with surface hydroxyls, whereas CEA monomers interact through the formation of ionic carboxylate binding to aluminum atoms within the oxide. The coated particles demonstrate enhanced miscibility in common organic solvents and monomers while MPS and PAM coatings are additionally shown to inhibit oxidation of the aluminum particles when exposed to aqueous environments at room temperature while PAM coatings are stable at even at elevated temperature.