Multiscale Insights Into the Graphene Oxide‐Induced Optimization of Silicate Chain Structure in C‐S‐H Gels

ABSTRACT The experiment used Ca(NO 3 ) 2 ·4H 2 O and Na 2 O·nSiO as calcium and silicon sources, respectively, to synthesize calcium silicate hydrate (C‐S‐H) via a hydrothermal method under anoxic conditions. Additionally, molecular dynamics (MD) simulations were employed to investigate the influence of graphene oxide (GO) on the microstructure of the C‐S‐H gel network. The results show that, although GO did not significantly increase the overall polymerization degree of the gel system, it effectively suppressed the formation of branched structures and specific configurations in the silicate chains, while significantly enhancing the mean chain length (MCL) of the silicate chains. The 29 Si MAS NMR results indicate that the incorporation of GO led to an approximately 105.1% increase in the MCL of the gel system. Mechanical test results show that the involvement of GO increases the compressive strength of the specimen by about 40.1%. MD simulation data indicate that GO effectively optimized the Q n distribution of silicon atoms in the gel network. The overall polymerization degree increased by approximately 6.2%, with the proportions of Q 2 and Q 3 configurations increasing by approximately 7.8% and 21.2%, respectively. This study is no longer limited to the overall gel network; it further fills the research gap on how GO affects the structural evolution of silicate chains, providing a theoretical foundation for the development of cement‐based composites.