Self-Assembly of a Layered 2D Molecularly Woven Fabric - Data Set

Paragraph Fabrics, materials consisting of layers of woven fibres, are some of the most important materials in everyday life. Previous nanoscale weaves include isotropic crystalline covalent organic frameworks (COFs) that feature rigid helical strands interlaced in all three dimensions rather than the 2D layers of flexible woven strands that give conventional textiles their characteristic flexibility, thinness, anisotropic strength and porosity. A supramolecular 2D kagome weave and a single-layer, surfacesupported, interwoven 2D polymer have also been reported. However, despite being proposed on a number of occasions, the direct, bottom-up, assembly of molecular building blocks into linear organic polymer chains woven in two-dimensions has remained elusive. Here we demonstrate that anion and metal ion template woven molecular ‘tiles’ can be tessellated into a material consisting of alternating aliphatic and aromatic segmented polymer strands, interwoven within discrete layers. Connections between slowly precipitating pre-woven grids, followed by the removal of the ion templates, results in a wholly-organic molecular material that forms as stacks and clusters of thin sheets, each sheet up to 100s of m long and wide but only ~4 nm thick, in which warp and weft single-chain polymer strands remain associated through periodic mechanical entanglements within each sheet. Atomic force (AFM) and scanning electron (SEM) microscopies show clusters and, occasionally, isolated individual sheets that following demetallation have slid apart from others they were stacked with during the tessellation and polymerisation process. The layered 2D molecularly woven material has long-range order, is birefringent, twice as stiff as the constituent linear polymer, and delaminates and tears along well-defined lines in the manner of a macroscopic textile. When incorporated into a polymer-supported membrane it acts as a net, slowing the passage of large ions while letting smaller ions through. The findings open up new opportunities and research directions for molecular materials made of flexible polymer chains mechanically woven at the nanoscale in two (or three) dimensions.