Development of a superhydrophobic and bactericide organic topcoat to be applied on thermally sprayed aluminum coatings in offshore submerged components

摘要

Marine environment is a very aggressive working atmosphere, where metals are subjected to corrosion and biological attacks, among other phenomena. The protection of steel components and structures has been achieved by means of protective coatings, including coatings with antifouling characteristics to avoid microbiological corrosion. In this work, an organic topcoat usually applied on top of Thermally Sprayed Aluminum (TSA) coatings has been functionalized. The paint was provided with superhydrophobic and antibacterial properties by the addition of SiO2 nanoparticles and biocide agents to its composition. Three biocide agents were evaluated, and the most promising one was selected. The evaluations performed comprised wettability tests, bacterial activity assessment, ecotoxicity tests, adhesion measurements in aqueous marine environment, and weathering aging tests to evaluate the corrosion protection ability of the coatings for its use in aggressive atmospheres. The paint containing a 25% Ind of SiO2 and a 1.5 wt% Cu2O presented superhydrophobicity and antibacterial characteristics, with high adherence, low toxicity, and an adequate performance on the weathering aging tests.