Mesoporous Silica Nanoparticles for Active Corrosion Protection

Abstract

This work presents the synthesis of monodisperse, mesoporous silica nanoparticles and their application as nanocontainers loaded with corrosion inhibitor (1H-benzotriazole (BTA)) and embedded in hybrid SiOx/ZrOx sol-gel coating for the corrosion protection of aluminum alloy. The developed porous system of mechanically stable silica nanoparticles exhibits high surface area (∼1000 m2·g(-1)), narrow pore size distribution (d∼3 nm), and large pore volume (∼1 mL·g(-1)). As a result, a sufficiently high uptake and storage of the corrosion inhibitor in the mesoporous nanocontainers was achieved. The successful embedding and homogeneous distribution of the BTA-loaded monodisperse silica nanocontainers in the passive anticorrosive SiOx/ZrOx film improve the wet corrosion resistance of the aluminum alloy AA2024 in 0.1 M sodium chloride solution. The enhanced corrosion protection of this newly developed active system in comparison to the passive sol-gel coating was observed during a simulated corrosion process by the scanning vibrating electrode technique (SVET). These results, as well as the controlled pH-dependent release of BTA from the mesoporous silica nanocontainers without additional polyelectrolyte shell, suggest an inhibitor release triggered by the corrosion process leading to a self-healing effect.

Smart Mesoporous Silica Nanocapsules as Environmentally Friendly Anticorrosive Pigments

“…Table 1 shows the BET surface area ( BET (m 2 /g)), pore volume ( (cm 3 /g)), and -potential (mV) obtained on the different nanoparticles. The BET and values obtained after calcination are in agreement with the typical reported values of similar mesoporous silica nanoparticles [32][33][34]. As can be observed, the significant decrease of the BET surface area and the pore volume after loading and especially after encapsulation confirms the success of the loading and encapsulation processes.…”

Emerging Corrosion Inhibitors for Interfacial Coating

“…One of the most commonly used methods is the direct addition of inhibitors in the primer or topcoat. However, a too high concentration or low solubility of the inhibitors often results in a deterioration of the integrity and physical barrier properties of the matrix of the protection system [101]. In addition, the existing interaction of the inhibiting agents with the protective matrix often leads to significantly reduced stability of the protective layer and the deactivation of the inhibitors.…”

Self-healing coatings in anti-corrosion applications

“…In the considered example, CaCO 3 microbeads were used as containers [54]. Micro/nanocontainers can be incorporated into a polymeric coating [35,54,68,71], less often into a sol-gel coating [27,72], and sporadically into a metallic coating, e.g. one based on electrochemical nickel [73].…”