Chemically functionalized graphene oxide as the additive for cement-matrix composite with enhanced fluidity and toughness

Chemically functionalized graphene oxide (GOM) was synthesized by the chemical reaction of polyether amine with graphene oxide (GO). The mechanical properties, rheological properties, dispersion effectiveness, slump retention behavior and the mechanism of GOM modified cement were also researched. The results show that GOM have more effective toughing function than cement with GO. And GOM can increase the slump flow of cement. The slump flow, the dispersion effectiveness and slump retention of GOM modified cement increased with the increasing molecular weight of polyether amine. The main chain (sheets structure) of GOM adsorbed on the cement surface, and the branched chains (polyether amine) stretched into the water. The electrostatic repulsive forces of adsorption layers and steric hindrance of branched chains endowed the good fluidity of cement. (C) 2017 Elsevier Ltd. All rights reserved.