Adsorption capacity of water-oxidized lanthanum-doped aluminum alloy powder

The adsorption of nitrogen onto the surface of lanthanum-doped ultrafine aluminum (UFA) powder was studied before and after aqueous oxidation under relative adsorbate (Pa/Po) pressures from 0 to 1 using low-temperature nitrogen adsorption method in a volumetric static vacuum facility. The adsorption isotherms are considered for their compliance with the isotherms in the classification of S. Brunauer, L. Deming, U. Deming and E. Teller. The obtained results confirm that treatment of REM-containing powders with water leads already at room temperature to the formation of new phases and affects their morphology. It is shown that a large role in the properties of water-treated powders belongs to the nanopores formed between crystallites on the surface of particles in the process of oxidation with water and during subsequent thermal dehydration. The adsorption properties of Al – 3% La sample were examined by the following methods: analysis of adsorption-desorption isotherms of vapors (statistical volumetric method) based on nitrogen adsorption at 78 K, electron microscopic technique, and X-ray analysis. The specific surface area and porosity of the powders were calculated.