Papers by Author: Agnese Pavlova

Abstract: Extrusion is a perspective forming technology for obtaining objects with certain profile, important for the TiO2 application as biomaterial. Extruded samples were calcinated at 1100 °C, thermally treated in different atmospheres: at 1450 °C in air and at 1300 °C in vacuum. An approach was made to examine the adhesion and colonization intensity of Staphylococcus epidermidis and Pseudomonas aeruginosa on TiO2 ceramic in vitro. It was found that Ps.aeruginosa demonstrated higher adhesion and colonization intensity as S.epidermidis and TiO2 samples treated in vacuum demonstrated higher attachment of microorganisms as TiO2 samples treated in air. It was supposed that surface charge promoted the bacterial adhesion on the vacuum treated samples.

Abstract: In past years scientists have interest in new specific TiO2 properties, which result from oxygen and titanium ratio in ceramic. Recently such TiO2 applications as implantable biomaterials in medicine and photocatalysts in purification of waste water become very significant. High temperature vacuum treated titanium oxide ceramics become biologically active and decrease microbiological water pollution when used as electrodes in electrochemical water treatment. In most of these cases highly dense ceramics are requested. TiO2 low-temperature modification anatase and TiO2 high-temperature modification rutile was used during the investigation. Different additives were used to improve particle packing and increase green density of pressed pellets as well as following sinter density. During the investigation it was found that green density of the samples depends not only on powder characteristics such as particle size distribution, grain size, mineralogical composition of raw material, quantity and nature of additives used in mass preparation procedure but also on kind and magnitude of compaction and sintering conditions.