Title: Adsorption of Superplasticizers on Calcium Aluminate Monosulfate Hydrate
Author(s): Franco Massazza, Umberto Costa,
and Alessandro Barrila
Publication: Symposium Paper
Appears on pages(s): 499-514
Keywords: admixtures; adsorption; calcium sulfoaluminate hydrates;
dispersants; lignin and derivatives; melamine-formaldehyde resins;
plasticizers; thermal gradient; x-ray diffraction; zeta potential.
This work examines the course of the adsorption and the variations in the surface charge observed when monosulphate is dispersed in an aqueous or dimethylsulphoxide solution containing li-gnosulphonate, naphtalene formadehyde condensate and formaldehyde condensate. Melamine The adsorption isotherms obtained by using dimethylsulphoxide of Langmuir type. Are In the aqueous medium adsorption is characterized by a maximum beyond which it decreases. The measurements of Zeta potential carried out on monosulphate dispersed in solutions of the admixtures pointed out a nearly linear increase in the negative charge of the particles up to a value corresponding to the maximum of the adsorption isotherms; beyond this value the potential remains constant. The values of Zeta potential justify the dispersing effect caused by the admixtures due to repulsion among the particles.