Surface‐Modified Mesoporous SiO₂ Containers for Corrosion Protection

Abstract

The development of active corrosion protection systems for metallic substrates is an issue of prime importance for many industrial applications. The present work shows a new contribution to the design of a new protective system based on surface modified mesoporous silica containers. Incorporation of silica‐based containers into special sol–gel matrix allows for a self‐healing effect to be achieved during the corrosion process. The self‐healing ability occurs due to release of entrapped corrosion inhibitors in response to pH changes caused by the corrosion process. A silica–zirconia‐based hybrid film is used in this work as a coating matrix deposited on AA2024 aluminum alloy. Mesoporous silica nano‐particles are covered layer‐by‐layer with polyelectrolyte layers and loaded with inhibitor [2‐(benzothiazol‐2‐ylsulfanyl)‐succinic acid]. The hybrid film with nanocontainers reveals enhanced long‐term corrosion protection in comparison with the individual sol–gel films. The scanning vibrating electrode technique also shows an effective healing ability of containers to cure the corrosion defects. This effect is due to the release of the corrosion inhibitor triggered by the corrosion processes started in the cavities. The approach described herein can be used in many applications where active corrosion protection of materials is required.

Dodecylamine-Loaded Halloysite Nanocontainers for Active Anticorrosion Coatings

“…It is possible to deduce that dodecylamine load was in the range of a maximum of 13.4 wt.% (obtained from the difference of total mass loss in the presence and in the absence of dodecylamine from Tables 1 and 2) and a minimum of 12.2 wt.%, as discussed above. These estimates are reasonable and supported by other published papers Abdullayev et al, 2009;Fix et al, 2009;Skorb et al, 2009). Figure 2 shows the diffractograms for the samples of halloysite without and with treatment for 6 h in 2 mol/L sulfuric acid.…”

“…If 0.5% is discounted from the total (mass loss related to slope 3 in Figure 1A), 12.2% is obtained. This value makes sense, because in literature, a range of 5-10% of cargo is always reported for different nanocontainers Abdullayev et al, 2009;Fix et al, 2009;Skorb et al, 2009). These findings indicate that TGA technique is a good tool to estimate the inhibitor load in such inorganic nanocontainers.…”

‘Containers’ for self-healing epoxy composites and coating: Trends and advances

“…The similar corrosion inhibitor loaded halloysite nanotubes will be a promising candidate to generate self-healing anticorrosive epoxy protective coating for metals. Mesoporous silica was also used to load corrosion inhibitors for sol-gel protective coating for metal [79]. Maia et al [80] adopted a one step process including synthesis of silica nanocapsules (SiNC) and loading of corrosion inhibitor 2-mercaptobenzothiazole (MBT) which outlook the mass production.…”

Smart Mesoporous Silica Nanocapsules as Environmentally Friendly Anticorrosive Pigments

“…In order to avoid spontaneous delivery, encapsulation of loaded mesoporous nanoparticles is also helpful [9]. Among the possible different technologies for encapsulation, the Layer-by-Layer (LbL) deposition technology of oppositely charged species (polyelectrolytes, nanoparticles, enzymes, dendrimers, etc.)…”

“…To date, despite the great number of studies carried out worldwide and although some alternatives have shown good behaviour in certain conditions, no definitive solution has been found for the replacement of chromates by nontoxic pigments. Recent developments in surface science and technology open up new opportunities through the integration of nanoscale containers (carriers) loaded with active components into coatings [8][9][10][11][12]. Suitable nanoparticle design would allow the controlled release of the inhibitor in response to external stimuli (change in pH, temperature, physical breakage of paint film, etc.…”