Biological Activity and Bio-Sorption Properties of the Ti2C Studied by Means of Zeta Potential and SEM

The expanded Ti2C MXene phase was synthesized from the commercial Ti2AlC MAX phase using classical acidic aluminium extraction method. The individual expanded Ti2C sheets were characterized by the diameters of between 26 and 61 nm and formed the specific network of slit-shaped pores in the size range of 3-5 nm. The BET specific surface area of expanded Ti2C was ca. 42% higher in comparison with layered Ti2AlC. Our investigations results revealed that both Ti2AlC and Ti2C phases did not influence negatively the gram-positive bacteria commonly occurring in the natural environment. Moreover, the slightly intensified growth of Bacillus sp. strain was observed in the vicinity of tested Ti2AlC and Ti2C. The SEM investigations of the preferential sites for bacteria adsorption indicated the presence of minor apoptosis for only Bacillus sp. strain, especially when the cells were located between individual sheets of the expanded Ti2C. The zeta potential curves obtained for Ti2AlC and Ti2C in distilled water differed significantly in shape. The intensive peak towards zero zeta potential was observed for Ti2C. Adsorption of bacteria cells on Ti2C resulted in changing of its zeta potential to that of bacteria cells.