Adsorption of organic core-shell corrosion inhibitors on cement particles and their influence on early age properties of fresh cement paste

Abstract

The influence of copolymers on the material properties of cement-based materials is closely related to their adsorption and distribution in cement matrix. In this study, the adsorption of organic core-shell corrosion inhibitors based on poly(ethylene oxide)-b-polystyrene (PEO-b-PS) micelles on cement particles and their influence on the early age hydration and workability of cement paste were investigated. The results showed that the micelles rapidly adsorbed on cement particles surface within 40 s. At mesoscale, the micelles distribution was uniform in cement matrix; at microscale they were preferentially adsorbed on positively charged aluminates phases. Due to the efficient adsorption, the particle dissolution and precipitation of hydration products were impeded, leading to the slightly retarded early hydration of C3A; the workability of cement paste was improved, which was attributed to the better dispersion of cement particles associated with the altered surface potential of cement particles and steric hindrance effect provided by the micelles.