Polycarboxylate Superplasticizer-Modified Graphene Oxide: Dispersion and Performance Enhancement in Cement Paste

Graphene oxide (GO) significantly enhances cement hydration at the nanoscale; however, its tendency to complex and agglomerate with Ca²⁺ in cement paste remains an unresolved issue. To improve the dispersibility and enhance the reinforcing effect of GO in cement paste, polycarboxylate (PC) superplasticizer was used to disperse GO (PC@GO). This study uniquely divided PC into two parts, with one modifying GO and the other acting as a water-reducing agent, to explore the effects on GO dispersion and analyze the rheological, carbon emission, mechanical, and hydration properties of cement paste. The experimental results show that the dispersion of GO modified by PC was improved, resulting in a significant enhancement in the performance of the cement paste containing PC@GO. The flexural and compressive strength of cement paste containing PC@GO₄ cured for 7 days increased by 23.7% and 12.6%, respectively, meanwhile, the carbon-to-strength ratio (CI) decreased by 14.8%. In addition, the hydration acceleration period shortened by 7.50%, and the water absorption and porosity of the cement paste containing PC@GO₄ decreased by 35.2% and 45.3%, respectively. Incorporating PC@GO into cement paste significantly enhances the dispersion of GO, substantially improves its mechanical properties, and positions it as a promising solution for the development of high-performance cementitious materials.