Vacuum as a continuum medium forming energy inhomogeneities with a high energy density in the liquid phase

Abstract

A method for the formation of metal nanoparticles in a localized volume with a high energy density due to the flow of a pulsed electric discharge and the cavitation effect was studied. The mechanism of the formation of energy inhomogeneities providing for the generation of nanoparticles with a high specific energy intensity was considered. Dynamic heterogeneity forms in three stages. There is a breakdown of the inter-electrode gap and the formation of a vacuum volume filled with a vapor-gas medium. When the pressure inside the bubble increases, a pulsed gas discharge is ignited, thus generating metal nanoparticles. This leads to the formation of a localized volume in which the discharge energy reaches values of up to 106 K. The increase in energy in the bubble leads to its collapse, after which the metal nanoparticles pass from the high-energy (106) medium into water at room temperature, resulting in their hardening. Highly pure nanoparticles of various metals 5–15 nm in size are obtained; these can be grown on a single-crystal silicon surface at room temperature and positioned on the surface of porous materials and products of complex configuration.