A.A. Revina, S.V. Daineko, A.N. Bolshakova, N.A. Yashtulov, Z.M. Tomova, V.I. Zolotarevski

Nanosized silver and iron particles provide an increase in catalytic activity and a decrease in silver and iron percentage in industrial catalysts. An important role in the design of nano modified catalytic layers is played by physicochemical studies of the dimensional and structural effects of nanoparticles that control the catalytic and adsorption properties of these structures in a liquid phase and as reaction cites on solid surfaces. Here, we carry out the characterization of silver and iron nanoparticles in liquid and solid phases and study the evolution of their parameters during a phase transition. Optical properties and the sizes of silver and iron metals nanoparticles, produced by a method of chemical reduction of ions in reverse micelles are compared. Optical properties of reverse-micelles with nanoparticles of metals were studied spectrophotometrically, and their sizes were determined by two methods - atomic-force microscopy and dynamic scattering. Also the optimum method of preparation samples for atomic-force microscopy research of metals nanoparticles has been chosen. Silver and iron nanoparticles were manufactured by the radiation-chemical reduction of ions under anaerobic conditions in aqueous-organic solutions. To a 0.15 M micellar solution of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in isooctane, a solution of 0.6 М (NH4)2Fe(SO4)2 - 6H2O) and 0,6 М AgNO3 was added to achieve an extent of hydration ω0 (water to surfactant substance ratio) of 1.0-8.0. The resulting slurry was first solubilized using a UZDN_2T ultrasonicator; then, the thus prepared solution was saturated with an inert gas to scavenge oxygen and irradiated with 60Co gamma radiation on a GURKh 100 000 setup (Institute of Electrochemistry, Russian Academy of Sciences). The radiation dose was varied from 5 to 30 kGy. After a capsule is sealed out, metal nanoparticles manufactured under anaerobic conditions can be stored in solution in the presence of atmospheric oxygen for long periods. The solution of our nanoparticles was a stable inverted micellar system: Mn+/H2O/AOT/isooctane. The optical absorption spectra of the silver and iron nanoparticles were studied as depending on the size of the reversed micelle water pool (ω0). The shapes and sizes of adsorbate nanoparticles were determined as a function of ω0 using an atomic-force microscope «BerMad 2000» «Nanotec Electronica» (Spain) (AFM).