Bactericidal Nanostructured Titanium Surface Through Thermal Annealing

Abstract

Inspired from nature, the antibacterial titanium (Ti6Al4V) alloy surface is developed through thermal annealing at 750 °C for 15 min. The titanium sample was coated with 5 nm thickness silver film using DC sputter coating and the thermal annealing was carried out in two different annealing environments (atmospheric and argon gas environment). The annealed samples were characterized through field-emission scanning electron microscope (FESEM). The formation of nanostructured topography on the annealed samples depends on the annealing environment. The polygonal-shaped surface structure is observed when annealed in atmospheric condition, and nanospikes were seen on titanium surface after annealed in an argon environment. The X-ray diffraction (XRD) analysis was carried out in order to investigate the phase formation during annealing. Plate counting method was used to study the bactericidal capability of modified titanium surfaces. The modified titanium surface in argon gas environment has shown better bactericidal property compared to surface annealed in an atmospheric environment. The physical contact killing mechanism of nanospike with the bacterial cell is dominant on the nanospike-structured titanium surface.