Enhancement of Active Corrosion Protection via Combination of Inhibitor-Loaded Nanocontainers

Abstract

The present work reports the synthesis of layered double hydroxides (LDHs) nanocontainers loaded with different corrosion inhibitors (vanadate, phosphate, and 2-mercaptobenzothiazolate) and the characterization of the resulting pigments by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The anticorrosion activity of these nanocontainers with respect to aluminum alloy AA2024 was investigated by electrochemical impedance spectroscopy (EIS). The bare metallic substrates were immersed in dispersions of nanocontainers in sodium chloride solution and tested to understand the inhibition mechanisms and efficiency. The nanocontainers were also incorporated into commercial coatings used for aeronautical applications to study the active corrosion protection properties in systems of industrial relevance. The results show that an enhancement of the active protection effect can be reached when nanocontainers loaded with different inhibitors are combined in the same protective coating system.

Self-healing coatings in anti-corrosion applications

“…Figure 6 schematically shows how a capsule is created using the particular methods [29]. As the building material, the following are used: poly(urea-formaldehyde) (PUF) [32][33][34][35], melamine-urea-formaldehyde (MUF) [35,36], phenol-formaldehyde [37], epoxy resin [38,39], methylene diphenyl diisocyanate (MDI) [40], poly(methyl methacrylate) (PMMA) [41,42], polystyrene [32,41], poly(allylamine) [43], polyvinyl alcohol (PVA) [43,44], polyurethane [40], polyphenol, amphiphilic block copolymers (polypyrrolidones, poly(ethylene oxide) [31], poly(caprolactone)) [31,32], cerium molybdate [45], zinc and aluminium nitrate [46,47], silica [27,32,[48][49][50], silver [42], gold [51], copper(II) sulphide [51], c-AlO(OH) [51], tin(IV) oxide [51] and titania oxides [42,52,53] and CaCO 3 microbeads [54]. The capsule material and the way of preparing capsules affect their shape and size.…”

“…Despite their clear advantages, such coatings have one major drawback: self-healing is possible only in the case of the first damage to the coating. Moreover, the incorporated particles may adversely affect the adhesion of the coating to the substrate [31,46,67,75,76]. In order to minimize this adverse effect, the micro/nanocontainer material should be matched to the coating material.…”

Antimacrofouling Efficacy of Innovative Inorganic Nanomaterials Loaded with Booster Biocides

“…This enables the controlled release of the biocide and, therefore, provides a safe environmental loading of the biocide together with specific targeting. A similar technology of nano-containers loaded with active compounds is already used in drug delivery [13], medical sensory applications [14], and for protection against corrosion [15]. Similarly, the technology of nano-containers for antifouling purposes has been explored in order to assess antifouling applications.…”

“…LDH are anionic clays with a typical lateral-size ranging from 20 to 40 nm [15,23], functioning as host-guest materials [24]. Both nanomaterials have already been successfully used for corrosion protection [15,[21][22][23] and more recently for fouling control, through the immobilization of different active compounds, including the above-mentioned pyrithiones, in the scope of the BYEFOULING FP7 project [25].…”

Corrosion protection of AA2024 by sol–gel coatings modified with MBT-loaded polyurea microcapsules

“…Thiazole and triazole derivatives are known to be efficient corrosion inhibitors for AA2024 due to their chemisorption ability in the copper-rich intermetallic particles [8,11,12,19] and have already been encapsulated into different inorganic [20,21] and polymeric reservoirs [22].…”