Synthesis of Hetero-Dimensional Mechanically Interlocked Networks

Mechanically interlocked polymer networks feature non-covalent topological constraints between chains, in which the sliding of rings along axles allows adaptive deformation and energy dissipation. Yet these interlocking sites cannot cooperate, and the lack of direct stress transfer pathways between them leads to localized stress concentration at the chain level. Here, we report the synthesis of hetero-dimensional mechanically interlocked networks (HDMINs), in which nanoporous two-dimensional molecular sheets serve as multi-threading platforms, each rigid sheet coupling its threaded chains into one cooperative network. One-dimensional chains threaded through two-dimensional polyaramid sheets in solution are captured by covalent crosslinking into a 2D/3D architecture. The mechanical bonds are preserved in this interlocking network, and their sheet-coordinated sliding relieves local stress concentration and enhances energy dissipation. HDMINs are simultaneously stiffer, stronger and tougher than their non-interlocked counterparts, showing that elevating the dimensionality of interlocking components converts discrete mechanical bonds into a cooperative network that bears load collectively.