Preparation And Supershydrophobic Modification Of TiO₂ Nanotube Arrays And Research On Its Anticorrosion Propeties

With the continuous development of human society, Human beings are getting more and more information about ocean. Since corrosion is very severe in sea-water, development of corrosion-resistant materials is a great research topic. TiO₂ is a semiconductor material with unique photo-electrochemical properties, electron-hole pairs will be produced under illumination. If TiO₂ is in contact with metal, electrons are injected to the metal. As a result, the potential of the metal will be negative than the potential at which the metal beings to oxidize. The metal can be protected from corrosion without dissolve of TiO₂. The investigation of TiO₂ for protection of metals has received great attention. TiO₂ nanotube array has not only improved"Photo-generated cathode Protection"properties but also higher specific surface area which is suitable for super-hydrophobic modification. Because super-hydrophobic surface has attracted much attention for its anti-corrosion application in recent years, we have prepared a super-hydrophobic surface on TiO₂ nanotube arrays. The corrosion behavior of super-hydrophobic surface was also investigated.First, Different surface morphology of TiO₂ nanotube arrays were formed by anodization of Ti foils in ethylene glycol-containing electrolytes. The results of SEM and TEM investigation show that excessive corrosion of TiO₂ nanotube will occur under high voltage and viscosity of electrolyte. There is a linear relationship between the viscosity, voltage and the excessive corrosion of TiO₂ nanotubes. The results of XRD show that TiO₂ nanotube arrays is amorphous and will become anatase phase under 450℃. Results of potentio-dynamic polarization measurements show that, due to the TiO₂ barrier layer exist under TiO₂ nanotube arrays, the corrosion resistance of titanium increase in certain degree.Second, based on the TiO₂ nanotube arrays with appropriate surface roughness, super-hydrophobic modification in (HMDS) solution is reported in this article. The surface structure and composition were characterized by means of water contact angle measurement, energy dispersive X-ray spectrum (EDS) and scanning electron microscopy (SEM). The results show that, with contact angle higher than 150°, the super-hydrophobic modification was successful. The results of potentio-dynamic polarization measurements and electrochemical impedance spectroscopy (EIS) show that the corrosion resistance of the material was improved remarkably. Moreover, it was also reported that the super-hydrophobic surface was more stable under dark conditions than under sunlight.