Properties of hydrophobic carbon-PTFE composite coating with high corrosion resistance by facile preparation on pure Ti

Composite coatings consisting of carbon and polytetrafluoroethylene (PTFE) were prepared on Ti alloy substrate by a simple two-step process of hydrothermal and impregnation. The morphology, composition, hydrophobic and corrosion properties of the composite coatings were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), water contact angle method, X-ray photoelectron spectroscopy (XPS) and electrochemical technique, respectively. The effect of PTFE content on the corrosion properties of the composite coatings was studied. It is found that the composite coating film exhibits a full coverage with uniformly distributed PTFE when 0.1 mol/L of glucose is used as carbon source and 20 wt.% PTFE suspension as impregnating solution. The coating with 20 wt.% PTFE has a good bonding strength with Ti plate and exhibits excellent hydrophobic property with a water contact angle of 142.3 degrees as well as superior corrosion resistance with corrosion current density as low as 0.0045 mu A/cm(2). With regard to its excellent hydrophobicity and corrosion resistance, the carbon-PTFE composite coating may find potential application in automobiles and metal corrosion industries.