Hard materials typically lack the mechanism of energy dissipation and cannot self-heal.Nature addresses this challenge by creating multiscale interfaces between high-contrast materials,namely minerals and biopolymers....Hard materials typically lack the mechanism of energy dissipation and cannot self-heal.Nature addresses this challenge by creating multiscale interfaces between high-contrast materials,namely minerals and biopolymers.Inspired by the enamel-dentin junction in nature,an enamel-like crown consisting ofβFeOOH nanocolumns is interdigitated with a flexible self-healing layer.The iron oxide top layer has exceptionally high modulus and hardness,which is more resistant to cyclic deformation than the bottom layer.The latter however provides an additional pathway for viscous and plastic energy dissipation and enables self-healing by allowing upward polymer diffusion to seal the damage.Picture-frame crack patterns were observed under large loading conditions using microindentation,which localizes the damage at the indentation site.The bending properties can be optimized by varying the thickness of the bottom layer,and the crack induced by bending can be effectively captured at the interface without any delamination.The biomimetic tooth replicate is highly adhesive to a ceramic surface and shows an obvious inhibition effect against Streptococcus mutans,a significant contributor to tooth decay.Combined with ultralow thermal diffusivity,this has great potential as dental material.Learning from nature,our work thus provides a powerful pathway to broadening the scope of synthetic materials for dental replicates.展开更多
基金The use of human tooth samples for SEM observations is approved by Ethics Committee of Hospital of Stomatology,Jilin University(ethics number 2021-61).
文摘Hard materials typically lack the mechanism of energy dissipation and cannot self-heal.Nature addresses this challenge by creating multiscale interfaces between high-contrast materials,namely minerals and biopolymers.Inspired by the enamel-dentin junction in nature,an enamel-like crown consisting ofβFeOOH nanocolumns is interdigitated with a flexible self-healing layer.The iron oxide top layer has exceptionally high modulus and hardness,which is more resistant to cyclic deformation than the bottom layer.The latter however provides an additional pathway for viscous and plastic energy dissipation and enables self-healing by allowing upward polymer diffusion to seal the damage.Picture-frame crack patterns were observed under large loading conditions using microindentation,which localizes the damage at the indentation site.The bending properties can be optimized by varying the thickness of the bottom layer,and the crack induced by bending can be effectively captured at the interface without any delamination.The biomimetic tooth replicate is highly adhesive to a ceramic surface and shows an obvious inhibition effect against Streptococcus mutans,a significant contributor to tooth decay.Combined with ultralow thermal diffusivity,this has great potential as dental material.Learning from nature,our work thus provides a powerful pathway to broadening the scope of synthetic materials for dental replicates.
