OF ANTIBACTERIAL ACTIVITY OF NANOSTRUCTURED TiO2 THIN FILMS
M. ENACHE, C. VĂCĂROIU, G. POPESCU, L. DUMITRU, A. BREZEANU, M.
GARTNER, M. ANASTASESCU
paper deals with investigation of antibacterial activity of TiO2 thin
films with various concentration of PEG (0.01–0.1M) and iron (1.23 and 7%)
in their composition or doped with nitrogen and followed by thermal
treatment at different temperatures (500–1000°C). The results revealed
that investigated thin films have antibacterial activity which is
influenced by coatings compositions and temperature of thermal treatment.
The optimum concentration of iron and PEG enhanced antibacterial activity
and induced some change for the surface structure which became congruent
with this antibacterial activity. The photocatalytic reaction is higher at
low iron content. The investigated nanostructures doped with nitrogen and
thermal treated at 600°C have a better antibacterial activity that
structures treated at 500°C. On the other hand, this activity has been
influenced by illumination time with white artificial light. The electron
microscopy investigations revealed that main effect towards microbial cell
are at the level of cell membrane and could be associated with cell
degradation, minivesicles formation, strong plasmolize and intracellular
vacuoles, cellular ghost and membrane fragments.