Editors: | F. Kongoli, F. Marquis, N. Chikhradze, T. Prikhna |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2019 |
Pages: | 174 pages |
ISBN: | 978-1-989820-10-0 |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Discovery of graphene as important materials carried out the coup in nanotechnology. Great interest to graphene testifies lots of articles, which are published monthly in the scientific literature. It seems that less attention is paid to chemical properties of carbon nanostructures. Carbon nanostructures have different functional groups that have the ability to react with various organic and inorganic compounds [1]. That is why it is possible to modify the carbon nanostructures by different compounds and then obtain organic and inorganic composites based on the above mentioned modified nanoparticles [2].
For the purpose of obtaining hard ceramic materials, graphene oxide was functionalized by organic compounds (polyvinyl alcohol (PVA), polyethylene glycol (PEG).Then, functionalized graphene oxide was added in alumina and the homogenization process was carried out in nanomill during 24 hours. Organic compounds are allocated from graphene oxide at high temperatures during sintering, leading to reduction of graphene oxide. This kind reduced graphene oxide has mostly similar properties as graphene, which have influence over the physical-mechanical properties of ceramics.
Concentration of modified graphene oxide is 1.5%w in composite. The obtained mixture is dried and then consolidated in a high temperature vacuum furnace at 1600°C under pressure at 478 kg/sm2.
The microhardness is 15.41 GPa (loading - 200 g) of the obtained ceramic materials in Fig 1. The microhardness is 12.025 GPa of the ceramic materials obtained from pure alumina under the same conditions. Testing was carried out using the Oliver-Pharr method according to the ISO-14577 standard. We are continuing works to determine optimal concentration of modified graphene oxide and we are researching other physical-mechanical properties [3].