Influence of Shear Deformation on Carbon Onions Stability under High Pressure

The influence of shear deformation on carbon onions stability under high pressure up to 45 GPa was investigated in a Shear Diamond Anvil Cell (SDAC) by the Raman spectroscopy and the Transmission Electron Microscopy (TEM). At shear less then 40 degrees the carbon onions are stable up to 30 GPa. Biger shear deformation leads to increasing of size and destruction of the onions and to formation of sp3 C-C bonds. At pressure exceeded 45 GPa shear deformation leads to diamond-like carbon (DLC) formation. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3501

Graphene-alumina nanostructured hybrid: synthesis with use dodecylamine and physicochemical properties

Combination of sol–gel and sonochemical techniques is suggested for producing a nanostructured graphene–alumina hybrid, which is a promising raw material for manufacturing fine-grained ceramics. This study focuses on the use of dodecylamine both in the sol–gel synthesis of Al-containing particles and in sonochemical graphene exfoliation. It has been shown that, when forming graphene–alumina composite in a reaction mixture of Al-containing sol and graphene suspension, graphene sheets take part as a template in the formation of a hybrid structure. Graphene sheets orient sol particles on their surface due to van der Waals interaction and control growth and direction of oligomeric gel chains. The graphene sheets limit the growth of Al-containing particles, which leads to an increase in the specific surface of the hybrid as compared to an alumina powder sourced from the same sol. The proposed approach enables the preparation of chemically homogeneous composite nanopowders with uniform distribution of components. © 2020 Taylor & Francis Group, LLC