Side-Chain Poly[2]rotaxane-Toughened Graphene Films

Graphene-based films are highly valued for their superior conductivity, thermal stability, and mechanical strength, yet their brittleness and low ductility limit their full potential. Current toughening strategies for graphene-based composites mainly focus on interfacial reinforcement between polymers and graphene substrates. However, research on energy dissipation arising from the intrinsic properties of polymers remains limited. Herein, we develop a toughened graphene film (^PRrGO) incorporating side-chain poly[2]rotaxane (PR) bearing anthracene units, where both interfacial reinforcement and intramolecular motion contribute to energy dissipation, greatly upgrading the film's mechanical properties. Results show that ^PRrGO films exhibit a tensile strength of 183 MPa, strain at break of 20.9%, Young's modulus of 896 MPa, and toughness of 17.2 MJ/m³, which are 4.27, 2.37, 1.25, and 8.33 times higher than those of original rGO films, respectively, while significantly outperforming conventional polymer-modified graphene films (^CrGO). Molecular dynamics simulations reveal a synergistic toughening mechanism: the intramolecular motion of side-chain [2]rotaxane units and the π-π interactions with graphene nanosheets. This study exploits the application of PRs in graphene engineering and provides unique insights into enhancing the performance of two-dimensional materials.