Incorporating graphene oxide into lime solution: A study of flocculation and corresponding improvement

The dispersion behavior of graphene oxide in cement matrix is one important factor in enhancing cement performance. In this work, we investigated the dispersion of graphene oxide in cement by simulating alkaline environment with a solution of calcium hydroxide and studied the corresponding strategy of improving dispersion. The obtained results showed that graphene oxide would flocculate even if calcium hydroxide concentration was very low, which might be the main reason of the unstable properties of the graphene oxidedoped cement. In addition, we discovered that, compared to -OH group, the -COOH group and the long chain of polycarboxylate-based superplasticizer were more effective in delaying the flocculation of graphene oxide. Finally, we proposed a dispersion mechanism of polycarboxylate-based superplasticizer. The study provides inspiration for the design of graphene oxide-doped cement materials.