Doubling the coating-substrate pull-off strength by growth of CaCO₃ nano-crystals
Abstract
Strong coating-substrate adhesion is crucial for ensuring long-term durability and performance of protective coatings in various applications. The growth of nano crystals on the substrate may be a preferable way to enhance the coating-substrate interactions. Here, an accelerated carbonation curing (ACC) scheme (0.5 MPa CO₂ gas pressure) was designed to grow calcium carbonate (CaCO₃) nano-crystals on a mortar substrate at early age before coated with a waterborne epoxy resin (WER). Microstructures of the ACC-treated mortar specimens and the coating-substrate interfaces were characterized by multiple microscopic tests, and the compressive strength of the carbonated substrate and the pull-off coating-substrate strength were measured. Results showed that the ACC treatment not only increased the mortar strength (by up to 17%), but also greatly improved the pull-off strength (by up to 112.2%). Substrate failure took place in the mortars after the ACC treatment. The mechanisms of physical adhesion, surface roughness, and crystals anchoring caused by the growth of pillar-like CaCO₃ nano-crystals may account for the largely raised pull-off strength. The findings would deepen the understandings of interfacial adhesion mechanisms between polymer coatings and cement-based substrates and provide new insights into developing stronger coating-substrate adhesions. Show more
Publication status
publishedExternal links
Journal / series
Chemical Engineering JournalVolume
Pages / Article No.
Publisher
ElsevierSubject
Pull-off strength; CaCO3 crystals; Carbonation; Interface; Crystals anchoring; MechanismOrganisational unit
09593 - Angst, Ueli / Angst, Ueli
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