Morphology, Sizes and Oxidation of Composite Copper Nanopowders, Obtained by an Electron Beam with Different Energies

Copper nanopowders were obtained by the gas-phase method under the influence of an electron beam of different powers. Thermodynamic modeling of the phase equilibrium state of the Cu-O2-C system during heating in argon and atmospheric pressure was carried out using the TERRA software package. The obtained nanopowders of copper were studied by X-ray phase analysis and transmission electron microscopy. The morphology, structure, size distribution, and average size of copper nanoparticles are determined. The dependence of the content of copper oxides in a copper-containing nanopowder on the electron beam power has been established. It is shown that copper nanopowders obtained at high power are not oxidized.

ACUTE TOXICITY OF THE MINERAL COMPLEX BASED ON NANOPOWDERS OF IRON, COPPER AND ZINC AFTER A SINGLE INTRAPERITONEAL INJECTION

An injection form of the mineral complex consisting of a mixture of iron, zinc and copper nanopowders has been proposed. According to the results of studies the injection form of the drug based on metal nanopowders belongs to the V-VI class of practically non-toxic, relatively harmless drugs by Hodge and to the 5th class of toxicity in accordance with GOST 32644-2014.

Measuring the Changes in Copper Nanopowder Conductivity during Heating as a Method for Diagnosing its Thermal Stability

This work researches the impact of the temperature of compacted copper nanopowder on the amperage of the current flowing through the nanopowder sample. It was determined that upon reaching its oxidation temperature (~ 1900C), the copper nanopowder started conducting electricity, and at 280-320°C electric breakdown of sample was occurring. This is caused to irreversible processes taking place in nanomaterials during heating, such as sintering and mass-transfer, those processes leading to the formation of conductivity channels. This speaks in favor of an evident dependency between copper nanopowder conductivity and the chemical transformations taking place in it; this allows for recommending this research method for instant diagnostics of copper nanopowders.

Synthesis of Carbon Nanofibers on Copper Nanopowders by Low-Temperature CVD

The article presents the results of experiments on the synthesis of carbon nanofibers by thermal chemical vapor deposition using copper nanopowders obtained by electric explosion of wire as catalysts. Stable growth of carbon nanofibers was carried out at temperatures significantly lower than normally used. The process parameters that are optimal for low-temperature growth of carbon nanofibers have been identified during the performed experiments. The synthesized samples have different diameters and morphology (from spiral to direct). Copper clusters are both at the ends and inside the fibers. The results of IR spectroscopy indicate that the structure of the obtained carbon nanofibers is polymeric. X-ray analysis revealed the presence of a halo on the diffraction patterns at small values of the angle 2θ, which proves that the grown<br />structures have an amorphous nature. There are no groups that are responsible for long-range order in all Raman spectra. Studies by transmission electron microscopy showed that nanostructures do not have an internal channel and nanofibers are solid.