Molecular dynamics of C-S-H production in graphene oxide environment

Abstract

The process of calcium silicate hydrate (C-S-H) generation in graphene oxide (GO) nanoslits was investigated via molecular dynamics simulations using the structural polymerization reaction of silica chains in the synthesis of silica gels. The structural evolution of C-S-H, radial distribution functions, chemical components, and distribution of Qn units in the system were analyzed to investigate the influence of GO on the early growth mechanism of C-S-H and compare the structural differences of C-S-H in the presence and absence of GO. The results showed that the proportion of silicon atoms bonded to bridge-site oxygen atoms in the C-S-H structure increased in the presence of oxygen-containing graphene groups. Ion adsorption in the GO surface layer led to an increase in the degree of polymerization of C-S-H. The nucleation and templating effects of GO were confirmed, revealing the intrinsic mechanism for the formation of GO-modified reinforced cementitious materials.