Multilevel molecular weaving.

The emergence of molecular weaving provides a bottom-up strategy for topological control of material properties. However, current molecularly woven polymer networks are fundamentally limited by their single-level woven structures, containing only one type of woven topology. Here we present a two-dimensional, multilevel woven polymer network that incorporates multiple woven topologies, similar to the structure of macroscale complex fabrics. Single-crystal X-ray analysis and integrated low-dose and cryogenic electron microscopy imaging confirm the presence of a multilevel woven structure. In situ pressure-dependent Raman spectroscopy combined with theoretical calculations reveals a hierarchical stress-regulation mechanism in the multilevel woven polymer network distinct from that of its single-level counterpart. Breakthrough experiments simulating industrial separation processes further demonstrate that the synergistic channels generated by the multilevel woven topology provide distinct advantages for precise toluene/methylcyclohexane separation. Hence, the transition from single-level to multilevel woven topologies is not merely a structural upgrade, but introduces unique properties and functions that lie beyond the reach of single-level systems.