Polycarboxylate superplasticizer-modified graphene oxide for enhanced dispersion and mechanical properties in cement-based composites
Le résumé fourni par la source
Owing to its high specific surface area and abundant oxygen containing functional groups, graphene oxide (GO) has considerable potential for improving cement based composites. However, its poor dispersion stability in alkaline hydration environments promotes nanosheet aggregation, which compromises the performance of cementitious materials and limits its reinforcing efficiency. In this study, a polycarboxylate superplasticizer (PCE) was employed to modify GO, aiming to enhance its dispersion stability and interfacial compatibility in cement systems. The effects of the GO-PCE composite on hydration, rheological behavior, pore structure, and mechanical performance were systematically evaluated using FTIR, UV-Vis spectroscopy, ζ-potential analysis, isothermal calorimetry, mercury intrusion porosimetry, SEM-EDS, and compressive strength testing. FTIR results indicated possible interactions between GO and the PCE-containing components, which may contribute to improved interfacial compatibility. The ζ-potential analysis indicated that the 10GO-PCE system at a dosage of 0.5% exhibited the highest absolute ζ-potential among the tested formulations (|ζ| = 34.6 mV), while UV-Vis spectroscopy provided qualitative information on their formulation-dependent optical responses and short-term suspension stability. Calorimetry results showed a cumulative heat release of 300.9 J/g and a total reaction heat (Qmax of 480.77 J/g. MIP and SEM-EDS revealed the densest microstructure with a median pore diameter of 17.22 nm, porosity of 14.14%, and Ca/Si ratio of 2.11. Correspondingly, the 28-day compressive strength reached 71.6 MPa, representing a 47.5% improvement over the reference sample. These results demonstrate that the synergistic interaction between GO and PCE enhances particle dispersion, hydration kinetics, and microstructural densification, thereby providing a potential approach for improving the performance of cement-based materials.
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