Preparation And Properties Of Anti-bacterial Nanocomposite Coatings On Aluminum

The traditionally antibacterial materials containing mercury salts, lead salts and so on were discontinued due to their toxicity and long remnant effective period. Although the antibacterial materials added organic bactericides possess good antibacterial properties, their periods of validity are too short. Recently, much attention has been paid to antibacterial nanoparticles such as TiO2, ZnO and SiO2etc, and especially to antibacterial nanocomposites in which Cu-TiO2nanocomposites exhibit a promising application due to a combination property of antibacterial Cu and TiO2. In the present paper, Cu-TiO2nanocomposite coatings are prepared on anodized aluminum by nanocomposite plating method, and their microstructure, corrosion resistance and photocatalytic property are investigated by using scanning electron microscope(SEM), energy disperse spectroscopy(EDS), electrochemical technology, UV spectra-photometer and atomic spectrophotometer. The experimental results are follows.The optimized process for preparation of Cu-TiO2nanocomposite coatings on anodized pure aluminum is obtained by systemically investigating the electrolyte temperature, current density, electroplating time, stirring speed, surface active agent and so on, it includes plating temperature25℃, current density2.5A/dm2, electroplating time1h, stirring speed300rpm, and surface active agent sodium dodecyl sulfate.The experiment results obtained by SEM/EDS show that the CU-T1O2nanocomposite coating is composed of spherical particles, polyhedron and lamellar particles, and its surface is smooth, less rough and compact. The composition of the nanocomposite coating mainly consists of Cu, O and Ti elements, showing its phase composition includes Cu and nano-TiO2particles.The electrochemical impedance spectroscopy and polarization curve of the Cu-TiO2nanocomposite coatings show that its corrosion potential increases200mV and its corrosion current density decreases one order of magnitude compared with those of pure aluminum, respectively, showing the Cu-TiO2nanocomposites possess better corrosion resistance than that of aluminum The degradation results of methyl orange by Cu-TiO2nanocomposite coatings indicate that the nanocomposite coatings possess a high photocatalytic performance. The degradation rate of methyl orange is obviously increases after the ultraviolet radiation for two hours. The measurement results of copper ion concentration show that the nanocomposite coating can release trace copper ions in water, and copper ions are beneficial to increase the photocatalytic performance of TiO? nanoparticles.