Titania (TiO2) nanoparticles were added to polydimethylsiloxane (PDMS) matrix to form nanocomposite coating via spin coating method on the AA 2024 (one of the aluminum alloys) to improve the anticorrosion ability of metal. The microstructures of the PDMS/TiO2 composite coating were detected by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrometry to verify the structure of composite coating. The corrosion properties of PDMS/TiO2 composite coating was evaluated by the electrochemical tests. The results showed that the anticorrosion ability of the composite coating has been significantly affected by the TiO2 content. For example, the impedance modulus value reached 106 Ωcm2 of the composite coating with 8 wt % nano-TiO2 fillers. Meanwhile, the corrosion current density (Icorr) of the coating was smaller than that of bare aluminum. The long term immersion experiments of coating were performed and the results demonstrated that the coating still had a protective effect on aluminum after 40 days of immersion.
Available online 3 February 2018