Authors:Monika Furko, Zsolt Fogarassy, Katalin Balázsi and Csaba Balázsi
A new method for preparing multi-layered graphene oxide powder was developed. In this method, the raw material was commercially available micro-sized graphite powder. The graphite powder was milled using a high speed attritor mill to reduce the particle size of the graphite to nanometer and to exfoliate the graphite into multi-layered graphene particles. The graphene particles were then oxidized into graphene oxide (GO) using the combination of strong oxidizing agents, thermal oxidizing, and sonication. Thorough morphological characterizations have been carried out to reveal the structure and the size of GO particles. The results confirmed that the oxidation process was successful.
Authors:Nikolett Oláh, Mónika Furkó, Zoltán May, Attila Sulyok and Katalin Balázsi
The aim of this article is to study the influence of TiC/a:C protective thin film on the corrosion and mechanical properties of sandblasted/polished Ti and TiAl6V4 substrates. The electrochemical corrosion behaviors of the samples were investigated in simulated body fluid (SBF) by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques at 7.4 pH and 37 °C. The metal ion release has been quantified by inductively coupled plasma optical emission spectroscopy (ICP-OES). The experimental results obtained from different electrochemical methods, ICP-OES, and scanning electron microscopy (SEM) showed that the TiC/a:C protective coating on sandblasted implant device improves the corrosion properties of the implant material and it is able to control the metal ion release. It was also shown that the hardness of the bare implant materials is improving by four orders of magnitude with the TiC/a:C nanocomposite coating beside a moderate elastic modulus value. The highest hardness (H) of ~28 GPa ± 3 was observed in the case of the film prepared at ~38 at% Ti content. Overall, the TiC/a:C thin film has suitable electrochemical characteristics for further consideration and assessment as a protective coating.