Depositation of sodium titanate nanotubes: superhydrophilic surface and antibacterial approach

Abstract

Here, the present work aimed to investigate the wettability of the sodium titanate nanotubes films and evaluate the antibacterial activity of the nanotubes powder under light and bacterial adhesion assay. The films were deposited by electrophoretic deposition technique on FTO glass and sodium titanate nanotubes were synthesized via microwave-assisted hydrothermal. Raman analysis, X-ray Diffraction, and Scanning Electron Microscopy confirmed the deposition of the nanotubes. Atomic Force Microscopy showed that the roughness of the films is superior to the roughness of the FTO. The water contact angle decreases from 37.85° (clean FTO) to 9.53° after deposition of the nanotubes. It reaches 0.00° after irradiation under ultraviolet light. The surface free energy of the FTO increases from 69.91 mN/m (clean FTO) to 81.43 mN/m after nanotube deposition and irradiation. Adhesion assays showed inhibition in Escherichia coli and a significant reduction in the adhesion of Staphylococcus aureus on the nanotubes films. Furthermore, in the antibacterial tests performed via the direct contact method showed a considerable inhibitory effect against E. coli (η=25.4%) under UV–Visible light than the dark conditions (η=4.1%). Therefore, nanotubes induce the photoinduced superhydrophilicity of the surface and enhanced inhibitory effect on E. coli after exposure under light due to the production of reactive oxygen species. E. coli and S. aureus have their adhesion inhibited in the nanotubes films probably due to high wettability and roughness at the nanoscale of the films.

Keywords

• FTO glass
• Titanate nanotubes
• Wettability
• Antibacterial activity
• Film