Synergistic effect of graphene oxide and hydroxylated graphene on the enhanced properties of cement composites

Abstract

Graphene oxide (GO) shows a remarkable reinforcing effect in the application of cement composite engineering while it also harms the workability of fresh cement slurry.

Enhancing Cementitious Composites with Functionalized Graphene Oxide-Based Materials: Surface Chemistry and Mechanisms

“…Additionally, the addition of HO-G significantly curbs the formation and expansion of microcracks through pore-filling and bridging effects. Moreover, it reinforces the resistance of the cement composite to chloride ion penetration ( Figure 3 a) [ 70 , 74 ].…”

“…Despite the significant strengthening effects of GO in various applications, its compatibility with cement composites could be improved [ 74 ]. However, the hydrophilicity of HO-G is heightened by the increase in hydroxyl content, rendering it dispersible in cement composites.…”

“…HO-G can be stably dispersed in cement slurry as a nanofiller without negatively impacting fluidity. However, regarding improving the flexural strength of cementitious composites, HO-G is inferior to GO [ 74 ]. The hydroxide or epoxide group weakens the adjacent C-C bond during the transition from sp 2 to sp 3 hybridization leading to a structural change from a honeycomb structure to a diamond-like structure.…”

“…Moreover, the weak ligand ability between HO-G and Ca 2+ results in weaker interfacial forces between HO-G and C-S-H [ 70 ]. Pu et al [ 74 ] conducted a study to investigate the effect of combining GO and HO-G on cement composites, considering their respective strengths and weaknesses. The experimental results showed that GO/HO-G composite additives exhibited excellent synergistic enhancement of material properties compared to the addition of GO or HO-G alone.…”

“…The hydrophilicity of GO nanosheets is partly attributed to the carboxylic groups located at their edges [ 74 ]. The production of ECG, which has the potential for carboxylation, is often achieved using ball milling, which is low-cost and high-yield.…”