Microcontainer-based waterborne epoxy coatings for AA2024-T3: Effect of nature and number of polyelectrolyte multilayers on active protection performance

New insights on the effect of nature and number of polyelectrolyte (PE) shells on active anticorrosion potential of microcontainers (MCs) applied as pH-sensitive reservoirs in coatings for the protection of AA2024-T3 is reported. Mesoporous silica particles (MSP) were loaded with benzotriazole (BTA) and shelled with different polyelectrolyte multilayers (PEM), demonstrating pH sensitivity. Weak-weak polyelectrolyte (W-W PE) shells allow immediate release of inhibitor, but weak-strong polyelectrolyte (W-S PE) shells encourage slower, more controlled and prolonged release, as revealed by release profiles of BTA from microcontainers. Active anticorrosion protection characterizations of the coatings doped with microcontainers were carried out by electrochemical techniques (EIS, SVET) and salt spray tests. Results reveal dependence of active properties of coatings on the nature and number of polyelectrolyte multilayers of microcontainers. We anticipate that proper choice of PEMs on smart containers can aid controlled functionalization of active feedback systems.