engleski

Performance of waterborne epoxy coating composite containing mesoporous silica nanoparticles as an intelligent host of corrosion inhibitors

The use of coatings is probably the most common and economically sound approach to improve durability and performance of metal products and constructions. To avoid negative effects of chromates which certainly could enable some active anticorrosion function to a passive matrix, and to attain an appropriate level of anticorrosion performance, while avoiding direct incorporation of corrosion inhibitors into coatings, where different obstacles can occur, the idea od self-protecting coatings with encapsulated inhibitors appeared. In this study, mesoporous silica particles are used as containers for corrosion inhibitors. The mesoporous silica nanoparticles, prepared with Stöber method, served as a host for two different corrosion inhibitors, 8- Hydroxyquinoline (Oxine) and 1- hydroxybenzotriazole (HOBT). Such nanoparticle composites were embedded in the waterborne epoxy coating in two different concentrations and applied to the steel test substrates. The concentrations of nanoparticles in the final cured coatings were calculated to be 0.69 wt% and 0.35 wt% for each inhibitor. Open circuit potential measurement, electrochemical impedance spectroscopy, salt spray chamber and humidity chamber testing followed by adhesion testing were used to investigate the protective properties of the composite coatings. Results showed higher corrosion resistance of the coatings embedded with the nanoparticles containing inhibitors, in comparison with the coating without nanoparticles. Release of the inhibitor form nanoparticles in response to corrosion damage were recorded during immersion in the NaCl media. Samples containing 1- hydroxybenzotriazole showed the best corrosion resistance properties during the test period. The percentage loss of adhesion properties after humidity chamber testing is similar for all samples but is more pronounced for samples containing nanoparticles after salt spray chamber testing.

mesoporous silica nanoparticles, inhibitors, self-protecting coatings, corrosion resistance

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