Mechanical reinforcement of bioceramics scaffolds via fracture energy dissipation induced by sliding action of MoS2 nanoplatelets

The inherent brittleness of bioceramics restricts their applications in load bearing implant, although they possess good biocompatibility and bioactivity. In this study, molybdenum disulfide nanoplatelets (MSNPs) were used to reinforce bioceramics (Mg2SiO4/CaSiO3) scaffolds fabricated by selective laser sintering (SLS). The fracture mode of scaffolds was transformed from transgranular to mixed trans- and intergranular. It could be explained that MSNPs could slide easily due to their weak interlayer van der Waals interactions and provide elastic deformation due to their high elastic modulus. Such sliding action and elastic deformation synergistically induced crack bridging, crack deflection, pull-out and break of MSNPs. Those effects effectively increased the fracture energy dissipation and strain capacity as well as changed the fracture mode, contributing to high fracture toughness and compression strength. Additionally, the scaffolds with MSNPs not only formed a bioactive apatite layer in simulated body fluid, but also supported cell adhesion and proliferation.