Intercalation of superplasticizer to layered calcium aluminate hydrate
Ten organic molecule models simulating the chemical functions of commercial superplasticisers used in the cement/concrete industry were intercalated into lamellar calcium aluminate hydrates to synthesise hybrid AFm phases.
AFm phases, encountered in cement hydration chemistry, belong to the large Layered Double Hydroxide (LDH) family. The intercalation process was performed using the anion exchange method. The affinities of the model molecules toward the AFm mineral layers, [Ca2Al(OH)6]+, were compared using several complementary techniques. They display the following tendencies: –PO32− –SO3− –CO2− for the hydrophilic parts and heptyl-R phenyl-R pentyl-R ethyl-R for the hydrophobic parts.
Various connection modes
The organic-inorganic interface of the hybrid AFm phases was achieved. The organic molecule arrangement is either perpendicular or parallel to the inorganic main layer, resulting in various connection modes, from intercalation to grafting. The results enable a better understanding of the chemical reactivity of the utilised superplasticisers during the concrete setting process.
The study is published in: Cement and Concrete Research Volume 110, August 2018, Pages 52-69.
