Corrosion resistance assessment of hybrid coatings in acid rain

The corrosion resistance of hybrid ZrO₂/PMMA and TiO₂/PMMA coatings in an artificial acid rain solution was evaluated using electrochemical techniques. ZrO₂ and TiO₂ ceramic phases were synthesized via alkoxide sol–gel, while the PMMA phase was created through polymerization. The resulting ceramic and polymeric phases were combined and applied as coatings on an aluminum alloy substrate, forming a continuous, homogeneous layer. Potentiodynamic tests showed reduced current density in TiO₂/PMMA and ZrO₂/PMMA coatings, lowering from 8.7 to 1.38 and 1.04 μA/cm², respectively, which indicated enhanced corrosion resistance in acid rain solution. Similarly, EIS results revealed high impedance values of 21.5 and 8.5 kΩ·cm² for ZrO₂/PMMA and TiO₂/PMMA coatings, respectively. These results demonstrated the coatings’ efficacy as physical barriers against corrosion. Scanning Electron Microscopy further complemented these findings, confirming improved structural integrity in the hybrid coatings.