Chemical structures and adsorptive behaviors of superplasticizers on β-C2S

Abstract

The chemical structures of four types of superplasticizers(SPs)and their adsorptive behaviors on β-C 2 S were investigated. The adsorption properties of SPs on β-C 2 S were measured and the relationship between the adsorption quantity and the specifi c surface of β-C 2 S was analyzed. The experimental results show that the adsorption quantity increases with the surface area increase of β-C 2 S, but the adsorption quantity per surface area is similar, which means that the main adsorbent is β-C 2 S itself. Polycarboxylic ester (PCE) showed the highest adsorption amount on β-C 2 S, followed by β-naphthalene sulfonates (NSF) and formaldehyde-acetone condensates sulfonates (FAS), amino sulphonate (AS) showed the least adsorption amount on β-C 2 S. PCE affected the surface potential of β-C 2 S particles in water differently in comparison with other types of SPs. The adsorption capacity of SPs on β-C 2 S is determined by factors such as molecular structure, functional groups and molecular weight of SPs.

Calcium complexation and cluster formation as principal modes of action of polymers used as superplasticizer in cement systems

“…In contrast, a similar study on β-C 2 S [39] revealed that the highest adsorption is achieved by PCEs and not by naphthalene sulfonates. Indeed, at increased polymer dosages PCE adsorbs in larger extent on C 3 S compared to PNFS (Fig.…”

Regulating the arm structure of star‐shaped polycarboxylate superplasticizers as a means to enhance cement paste workability

“…On the contrary, the fluidity retention showed positive correlation with the adsorption amounts and Zeta‐potential data. In fact, the PEO side‐chains density affected the adsorption of the PCEs onto the surfaces of the cement particles . According to Figure , the pH values decrease with the addition of SPCEs at different times.…”

Effects of connection mode between carboxyl groups and main chains on polycarboxylate superplasticizer properties

“…Polyethylene glycol side chains wrap around cement particles and display steric hindrance 4–6. The properties of PCs are determined by their molecular structure, and differential molecular structures of PCs may be synthesized using suitable monomers with PEG side chains through free‐radical copolymerization 7–10. A clear relationship appears to exist among structure, properties and monomers, and a ideal superplasticizer seem may be presumed to be synthesized by using suitable monomers; however, this is not the case.…”