Nano-engineering of the mechanical properties of tobermorite 14 Å with graphene via molecular dynamics simulations

The tensile and shear properties of tobermorite 14 angstrom-based structures reinforced with a single graphene sheet (GS) interfacing with either the surface water, octahedral calcium, or tetrahedral silicate layer were investigated using molecular dynamics simulations. The GS contributed to a significant increase in the XY-plane tensile (180%-360%) and shear (90%-225%) strengths, stiffness, and toughness while degrading the out-of-plane properties of the tobermorite structures. The water interface promoted molecular friction (intermolecular forces) and resulted in greater in-plane fracture tensile strength and toughness but a lower shear toughness than when the GS interfaced with the dry solid surfaces. (C) 2019 Elsevier Ltd. All rights reserved.