6533b82cfe1ef96bd128f4c0
RESEARCH PRODUCT
Intrinsic Acidity of Surface Sites in Calcium Silicate Hydrates and Its Implication to Their Electrokinetic Properties
Marialore SulpiziLuis PegadoChristophe LabbezSergey V. Churakovsubject
CementQuantitative Biology::BiomoleculesChemistryAb initioThermodynamicsThermodynamic integrationSorptionElectrolyteSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialslaw.inventionElectrokinetic phenomenachemistry.chemical_compoundPortland cementGeneral EnergylawCalcium silicate550 Earth sciences & geologyPhysical chemistry[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]Physical and Theoretical ChemistryPhysics::Chemical PhysicsComputingMilieux_MISCELLANEOUSdescription
Calcium Silicate Hydrates (C–S–H) are the major hydration products of portland cement paste. The accurate description of acid–base reactions at the surface of C–S–H particles is essential for both understanding the ion sorption equilibrium in cement and prediction of mechanical properties of the hardened cement paste. Ab initio molecular dynamics simulations at the density functional level of theory were applied to calculate intrinsic acidity constants (pKa’s) of the relevant ≡SiOH and ≡CaOH2 groups on the C–S–H surfaces using a thermodynamic integration technique. Ion sorption equilibrium in C–S–H was modeled applying ab initio calculated pKa’s in titrating Grand Canonical Monte Carlo simulations using a coarse-grained model for C–S–H/solution interface in the framework of the Primitive Model for electrolytes. The modeling results were compared with available data from electrophoretic measurements. The model predictions were found to satisfactorily reproduce available experimental data.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-05-23 |