Interaction of PCE polyelectrolytes with cement mineral surfaces: a study from the macro to the nano scale

Polycarboxylate-ether-based superplasticizers (PCEs) are fundamental cement admixtures which improve rheological properties of concretes and mortars. A multi-method approach is applied to combine rheology, adsorption, zeta-potential, atomic force microscopy (AFM), scanning electron microscopy (SEM), and secondary ion mass spectroscopy (SIMS) techniques. Influences of different electrolyte solutions, solid materials, polymer architectures and AFM tips are analyzed. This thesis demonstrates the importance of comparing macroscopic results with the nanoscale behavior of superplasticizers at the cement minerals surfaces. Furthermore, the study highlights the power as well as limitations of the AFM technique in studying PCE dispersion forces.