Anatase TiO₂ Nanocomposites for Antimicrobial Coatings

Abstract

A sol-gel chemistry approach was used to fabricate nanoparticles of TiO(2) in its anatase form. The particle size is shown to be sensitive to the use of HClO(4) or HNO(3) as acid catalyst. The gold-capped TiO(2) nanocomposites were processed by the reduction of gold on the surface of the TiO(2) nanoparticles via a chemical reduction or a photoreduction method. Different percentages of vanadium-doped TiO(2) nanoparticles, which extended the TiO(2) absorption wavelength from the ultraviolet to the visible region, were successfully prepared. The synthesized nanocomposites have a size of about 12-18 nm and an anatase phase as characterized by XRD, TEM, AFM, and UV-vis spectroscopy. The TiO(2) nanocomposite coatings have been applied on glass slide substrates. The antibacterial activity of TiO(2) nanocomposites was investigated qualitatively and quantitatively. Two types of bacteria, Escherichia coli (DH 5alpha) and Bacillus megaterium (QM B1551), were used during the experiments. Good inhibition results were observed and demonstrated visually. The quantitative examination of bacterial activity for E. coli was estimated by the survival ratio as calculated from the number of viable cells, which form colonies on the nutrient agar plates. The antimicrobial efficiency and inhibition mechanisms are illustrated and discussed.

Tuning the Photocatalytic Activity of Anatase TiO2 Thin Films by Modifying the Preferred <001> Grain Orientation with Reactive DC Magnetron Sputtering

“…Photocatalytic and superhydrophillic thin films of anatase TiO 2 have attracted large research interest since the early 1970s and find application as self-cleaning, anti-fogging and anti-bacterial coatings [1][2][3][4][5]. Due to their intrinsic beneficial physical properties, TiO 2 films are suitable for architectural coatings, and commercially available self-cleaning glasses, tiles, cement, porcelain based on TiO 2 already exist [6][7][8].…”

Antibacterial Activity Studies On Mg Doped Ceo2 Quantum Dots

“…In a typical procedure, 5.2g (0.4M) of Cerium (IV) nitrate (NH 4 ) 2 [Ce(NO 3 ) 6 ] in 25ml of deionized water aqueous mixed with Magnesium acetate (0.1, 0.3, 0.5 and 0.7 M.%) in 25ml of deionized water under constant stirring. The saturated solution of citric acid was added drop wise in to the mixture.…”

Impact of Annealing on Structural and Optical Properties of ZnO Thin Films by SILAR Method and its Antimicrobial Applications

“…The different cell wall is responsible for the variation in activity against these two types of bacteria. Gram-positive bacteria typically have one cytoplasmic membrane and thick wall composed of multilayers of peptidoglycan 18 . Whereas gram-negative bacteria have more complex cell wall structure, with a layer of peptidoglycan between outer membrane and cytoplasmic membrane 19 .…”