Self-repairing and strong materials

Nacre, which is also known as Mother of Pearl, is a naturally occurring composite formed from calcium carbonate and biopolymers that create a brickwork structure. It is also nearly a thousand times stronger than any of its component parts and a major target for biomimetic synthesis.

Construction of the brickwork structure is central to developing nacre-like materials with enhanced properties. Gaoquan Shi, and colleagues, at Tsinghua University, began by making a hydrogel from graphene and a silk protein, called fibroin.

Solution casting and drying this hydrogel gave parallel graphene plates bound with fibroin that self-assembled to create a material with a brickwork structure.

The team’s material is an improvement over other composites owing to a number of different factors. Graphene is stronger than the inorganic platelets that are commonly used but Shi explained that the homogenous composite hydrogel ‘produced an ideal layered structure’ which amplified the mechanical properties. Coupled with the strong electrostatic and hydrogen bonding between fibroin and graphene, the system surpasses most composites previously reported.

This is just one of many examples of self-repairing materials that have been developed by the study of the natural world. If you are interested in exploring more of these, please CONTACT US.