Responsive Polymer-Layered Silicate Hybrids for Anticorrosion

Abstract

Two-dimensional materials have been introduced in polymer coatings to increase the lifetime of metallic materials by providing barrier properties against corrosive species. Corrosion inhibitors can be inserted into a 2D filler to mitigate the corrosion of metallic materials caused by corrosive species. Current drawbacks of this approach include a poorly controlled release of the inhibitor and the incompatibility of the filler and polymer. To achieve long-term anticorrosion performance, a layered silicate (octosilicate) is modified by surface-graft polymerization with a monomer functionalized with a corrosion inhibitor, 8hydroxyquinoline. A pH-responsive polymer-inhibitor conjugate, poly(methyl methacrylate-co-8-quinolinyl acrylate), is covalently attached to the silicate and then provides a sustainable release of the corrosion inhibitor upon acidification. The corrosion current density of aluminum alloy substrates (AA2024) coated with poly(methyl methacrylate-co-butyl acrylate) embedding the octosilicate containers is decreased due to a synergistic effect of barrier properties provided by the 2D filler and the pH-responsive release of corrosion inhibitor. This conceptual design can be potentially applied to release molecules such as drugs, fertilizers, or pesticides.

Pickering Emulsion Gel Based on Funori Biopolymer and Halloysite Nanotubes: A New Sustainable Material for the Cleaning of Artwork Surfaces

“…1 μm, while the internal and external diameters are between 10–15 and 50–80 nm, respectively. ,, It is important to note that halloysite can be easily dispersed in water without the need for time-consuming exfoliation procedures required for other platy clays . Due to their attractive colloidal properties and versatile surface, , HNTs can be used in drug delivery, − catalysis, − remediation, − nanocontainers for anticorrosive compounds, , and conservation of cultural heritage. , It is reported that halloysite modified by anionic surfactants produce inorganic micelles with solubilizing capacity toward hydrophobic molecules. , The filling of polymeric matrix with halloysite is proper to fabricate composite materials with excellent mechanical performances, − vapor barrier properties, high thermal stability, − and flame retardant characteristics. , Halloysite possesses peculiar interface properties since its outer and inner surfaces are oppositely charged within a large pH interval. Specifically, the surface cavity is positive, and the shell is negative for pH larger than ca.…”