Synthesis of SiO_2-PCE Core-Shell Nanoparticles and its Modification Effects on Cement Hydration

摘要

NanoSiO_2 was widely used to modify the property of cementitious materials, however, for nanoparticles used in cement-based materials, key problem is the effective dispersion. The surface modification technology can be introduced to promote dispersion of nanoparticles in aqueous system, especially in cement pore solution, which possess high concentration of ions. In this study, at first, NanoSiO_2-polycarboxylate superplasticizer (SiO_2-PCE) core-shell nanoparticle was synthesized from silanized polycarboxylate superplasticizer and colloidal nanoSiO_2 by the "grafting to" method, then SiO_2-PCE was testified by UV-Vis, FTIR, and TGA. Additionally, stability of SiO_2-PCE and its effect on cement hydration were investigated. Results shows: SiO_2PCE possess higher stability in saturated calcium hydroxide solution compared to nanoSiO_2, and heat development of cement hydration can be regulated by shell structure of SiO_2-PCE. The research implied a new approach for nanoSiO_2 to optimize cement-based composites.