Granular Nanostructure: A Facile Biomimetic Strategy for the Design of Supertough Polymeric Materials with High Ductility and Strength.

The realization of high strength, large ductility, and great toughness for polymeric materials is a vital factor for practical applications in industry. Unfortunately, until now this remains a huge challenge due to the common opposing trends that exist when promoting improvements in these properties using materials design strategies. In the natural world, the cuticle of mussel byssus exhibits a breaking strain as high as 100%, which is revealed to arise from an architectural granular microphase-separated structure within the protein matrix. Herein, a facile biomimetic designed granular nanostructured polymer film is reported. Such biomimetic nanostructured polymer films show a world-record toughness of 122 (± 6.1) J g-1 as compared with other polyvinyl alcohol films, with a breaking strain as high as 205% and a high tensile strength of 91.2 MPa, which is much superior to those of most engineering plastics. This portfolio of outstanding properties can be attributed to the unique nanoscale granular phase-separated structure of this material. These biomimetic designed polymer films are expected to find promising applications in tissue engineering and biomaterials fields, such as artificial skin and tendon, which opens up an innovative methodology for the design of robust polymer materials for a range of innovative future applications.