Implications of weaving pattern on the material properties of two-dimensional molecularly woven fabrics

Abstract

Similar to macroscopic woven fabrics, molecularly woven polymers constructed from identical molecular strands but different weaving architectures are anticipated to display diverse physical and mechanical characteristics. Nonetheless, identifying these distinctions and comprehending the underlying mechanisms poses a significant challenge. Herein, we evaluate the impacts of different weaving patterns—plain, mix, and basket—on the characteristics of two-dimensional (2D) organic woven polymers through systematic all-atom simulation. Three weaves, consisting of the same molecular strands, are produced by adjusting the connections of the enantiomers of an inherently chiral 2×2 interwoven grid. Among the tested patterns, the plain weave exhibits superior stability, minimal structural deformation, and the most consistent pore size compared to others. The maintenance of the weaves in kinetically stable high-energy states is attributed to both aromatic stacking and hydrogen bonding interactions between warp and weft strands, while the alteration of weaving patterns leads to variations in the type and strength of these weak interactions. Despite the differences on the weaving pattern, the mechanical stress tends to localize at the contact field. Further analysis on impact resistance and in-plane stretchability highlights how weaving architectures influence the energy dissipation pathways and reinforce the mechanical properties of individual molecular chains. Simulation outcomes indicate that the disparities resulting from various weave patterns primarily stem from the total number and density of entanglements, as well as the interstrand non-covalent interactions. This research highlights the critical influence of weaving architecture on molecularly interlacing material properties, providing valuable insights for future invention and engineering of molecular-level weaving.