Suchergebnisse

The possibility of  Na2EDTA applying as a reducing and stabilizing reagent in aqueous medium to obtain gold hydrosols from hydrogen tetrachloroaurate was studied. It was found that, depending on the pH of the reaction medium, both nanosized precipitates (~60 nm) and gold hydrosols, consisting of spherical nanoparticles of uniform size (12–15 nm), can be obtained. Stable gold sols are formed at pH ≥ 10.5. Sol formation process rate depends on the temperature and concentration of  Na2EDTA and increases with their increase. An electrochemical study of processes of  HAuCl4 reduction and Na2EDTA oxidation showed that the possibility of gold hydrosols formation in an alkaline medium is due to the kinetic inhibition of the reduction process of gold hydroxo complexes formed during this process.

The Bi-activated strontium aluminates SrAl2O4 and Sr3Al2O6 are synthesised by the solid-phase method; their structural phase and spectral-luminescent properties are studied. The possibility of controlling the luminescence spectrum, its intensity and, consequently, the colour characteristics of the samples by changing the composition of the matrix, the nature of the activator and its concentration are shown.