ZnO and Simonkolleite Nanocomposite Synthesis via Green Chemistry Using Hibiscus Flower Extract

In the present work, zinc oxide (ZnO) and Simonkolleite (SK) nanocomposite was prepared using a facile green synthesis route, using hibiscus flower extract. Zinc chloride as starting solution was mixed with hibiscus plant extract. The zinc salt molarity was varied in order to investigate its effect on the synthetized nanocomposite structure. The synthetized nanocomposite were characterized by mean of X rays diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) and X-ray photoemission spectroscopy (XPS). The results indicated that the zinc chloride molarity plays a key role in zinc oxide and simonkolleite nanopowder synthesis. The increase in zinc salt molarity above 0.1M yields to a pure simonkolleite. While, at low zinc salt molarity, the formed nanoparticles are composed of mixture of simonkolleite and ZnO. The thermal treatment causes a partial conversion of simonkolleite to ZnO.

Application of the Method of Evaporation of a Substance by High-Energy Electron Beam to Produce Tungsten Nanopowder

The method of producing nanopowder by evaporation by a high-energy electron beam has a great potential for refractory substances, since the electron beam makes it possible to obtain high the power density in the interaction spot is not more than 3–4 cm2 and, as a result, high temperature gradients. The accelerator and electron beam have a high efficiency of transferring energy from the power grid to evaporation (up to 70 %). The electron beam does not introduce pollution and is not selective to the material. Work specifics with an electron accelerator is associated with radiation caused by electron deceleration and high temperatures. These phenomena greatly complicate the monitoring of processes occurring in the evaporation zone. Therefore, at present, the method requires development and adaptation to specific materials. In this work, we studied the process of obtaining nanosized tungsten powder by the indicated method. Experiments were tested that allow obtaining data on the processes of nanopowder synthesis by calorimetry of the evaporation zone and measurements of the radiation level near it. The technology was developed and the parameters of the obtained tungsten nanopowders were determined. Showing ways to increase productivity This method is applied to tungsten.

Features of Consolidation of Nanoceramics for Aerospace Industry

Nanostructured ceramic materials and compositions based on them find an increasing application in all branches of science and technology. At the same time, the performance properties of new ceramic nanomaterials (strength, adhesion, optical and others) are significantly different from properties of traditional ceramics, which were used before. The qualitative characteristics of nanoceramics are largely determined by the initial structure and methods of nanopowder synthesis, as well as by the characteristics of conditions and methods for their consolidation. This work is devoted to the synthesis of nanopowders and effective method of its sintering for the production of nanoceramic materials which have special mechanical properties, e.g. components with increased modulus of elasticity ("ceramic steel"), etc. It makes it possible to effectively use them in aerospace industry.