Thinner fillers, coarser pores? A comparative study of the pore structure alterations of cement composites by graphene oxides and graphene nanoplatelets

It is generally accepted that composites with thinner fillers would show more refined pore structure, so currently the uses of nano materials including nano graphene-based additives (NGAs) to fabricate functional cement composites are quite popular. However, the effects of NGAs on the pore structure of cement composites are far from being fully understood. In this work, we investigated the pore structure of cement composites blended with graphene oxides (GOs) and graphene nanoplatelets (GNPs), which show the similarly layered structure but different sizes and chemico-physical properties. Results reveal that both GOs and GNPs do not significantly alter the hydration products of cement. Both GOs and GNPs can make the material matrix denser by depressing the meso pores; and GOs tend to coarsen the macro pores due to the laminar agglomerations. The findings of this study help better tailor the pore structure of cement composites with NGAs for future materials design and manufacture.