Preparation of a three-dimensional modified graphene oxide via RAFT polymerization for reinforcing cement composites

Graphene oxide (GO) nanosheets own a large specific surface area and excellent mechanical properties. GO sheets can be dispersed in water to form nano dispersoid, and are easy to composite with cement-based materials. However, the dispersity of GO in alkaline cement slurry is inferior, which causes severe agglomeration, so that the enhancement effect of GO cannot be fully utilized. In this paper, GO-g-PPOE (GE) and GO-g-PPOE-b-PAA (GEA) were synthesized via RAFT polymerization on GO surface. The growth models of poly(poly(ethylene glycol) methyl ether methacrylate) (PPOE) and poly(poly(ethylene glycol) methyl ether methacrylate) -co- acrylic acid) (poly(POE-co-AA)) from GO surface were predicted by TEM and SEM. The result of Zeta potential proved that both GE and GEA effectively improved the dispersity of graphene oxide in cement pore solution. Due to the improvement of dispersity and the adsorption of metal ions in cement paste, GE and GEA promoted cement hydration, thereby reinforcing cement composites.