Graphene origami amplifies mechanical properties of polyethylene nanocomposites

Graphene and its derivatives have been widely used as reinforcing nanofillers for high-performance polymer nanocomposites. The effectiveness of the reinforcement largely depends on the properties of the nanofiller-matrix interface, which can be represented by the interfacial shear strength (IFSS). This work systematically investigates IFSS enhancements for polyethylene (PE) nanocomposites reinforced by graphene origami (GOri) through molecular dynamics pull-out simulations. When two-dimensional (2D) graphene is transformed into a three-dimensional (3D) origami structure, the resultant GOri/PE nanocomposite exhibits a higher IFSS due to the larger surface roughness of GOri and the associated higher van der Waals interaction strength between the filler and the matrix. Moreover, the incorporation of GOri into the PE matrix leads to more flexible and auxetic nanocomposites due to the unusual properties of GOri. The unique combination of high IFSS, high flexibility, and intrinsic auxeticity makes GOri/PE nanocomposites an ideal candidate for many practical applications, such as impact protection, flexible electronics, and soft robotics.