Work

Staining and adsorption of PCE superplasticizers in alkali-activated materials (AAM) investigated by fluorescence microscopy

Year: 2025

Type: article

Abstract: The spatial-dependent adsorption of polycarboxylate ethers (PCE) in alkali-activated materials was analysed using fluorescence microscopy after coupling PCE with a fluorophore marker. The adsorption has been derived from the fluorescence with the consideration of the pH-dependence of the fluorophore marker using two different PCE superplasticizers and two different fluorescent markers. The synthetic route of a staining reaction was successfully applied to IPEG PCE and APEG PCE superplasticizers, verified and quantified by different spectroscopic methods. The derived adsorption values were compared with the flowability by mini-slump tests and total organic carbon measurements. It was shown that low activator concentrations can increase the adsorption of a superplasticizer on particles of different precursors. Additionally, it was shown that in alkali-silicate activated systems PCE adsorb on particles while the functionality is lost. • PCE molecule adsorption visualised with fluorescence microscopy. • Distinct PCEs on different precursors in an activator demonstrate an increase in adsorption at low excitation levels. • The observed loss of efficacy of PCE in a silicate activator does not appear to be related to its adsorption.

Source: Construction and Building Materials

DOI: 10.1016/j.conbuildmat.2025.140659

Authors: Denis Kosenko, Alexander Wetzel, Bernhard Middendorf

Institution: University of Kassel

Language: English

Topic: Concrete and Cement Materials Research

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,540

Funders: Deutsche Forschungsgemeinschaft, Hunan University