▎ 摘　　要

Herein we report the synthesis of polystyrene-graphene nanosheets (PS-GNs) and octadecylamine-graphene nanosheets (OA-GNs) which possessed much rougher surface and wider lamellar spacing than that of the pristine GNs. The incorporation of PS and OA into the GNs mitigated the agglomeration issues of the pristine GNs. The synthesized PS-GNs and OA-GNs were in turn applied as additives to prepare modified cement mortars which were tested for various mechanical and fluidity tests. The test results showed that PS-GNs and OA-GNs incorporation played effective roles in reinforcing compressive strength and flexural strength of modified cement mortar. The results revealed that in contrast to the physical reaction of PS-GNs with the cement mortar, the chelating reaction of OA-GNs with Ca2+ retarded the hydration process at 0-7 days of cement mortar. This study provides important findings for the preparation of PS-GNs/cement mortar and OA-GNs/cement mortar with enhanced mechanical properties for practical applications in construction industries. [GRAPHICS]