The main aim of the research off my thesis was to form a protective oxide layer TiO2 on the Ni-Ti metal surface by carrying out the plasma oxidation of the Ni-Ti alloy. With the plasma treatment the corrosion resistance and the biocompatibility of the Ni-Ti alloy were increased, which are very important properties for medical applications. The plasma treatment was performed at pressure of 30 Pa in hydrogen and oxygen plasma with a different treatment times ranging from 5 s to 20 s. The untreated sample of Ni-Ti alloy was taken for comparison. All samples were analyzed by the X-Ray Photoelectron Spectroscopy (XPS), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Scanning Electron Microscopy (SEM) to determine the chemical composition of the surface and the oxide layers and the morphology and microstructure of the oxide layers. In order to asses biocompatibility of samples in vitro biological tests with a whole blood were performed.
We have shown that TiO2 oxide rich layer is formed with plasma, which does not contain Ni. The thickness of the TiO2 oxide layer increases by plasma treatment time. Changes of the colour of samples reflect the change of the oxide layer thickness. It was shown that the protective oxide layer of TiO2 on Ni-Ti alloy reduces adhesion and activation of platlets from whole blood.
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