Self-assembly of a layered two-dimensional molecularly woven fabric

Abstract

ParagraphFabrics, materials consisting of layers of woven fibres, are some of the most important materials in everyday life. 1 Previous nanoscale weaves [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] include isotropic crystalline covalent organic frameworks (COFs) 12-14 that feature rigid helical strands interlaced in all three dimensions rather than the 2D 17,18 layers of flexible woven strands that give conventional textiles their characteristic flexibility, thinness, anisotropic strength and porosity. A supramolecular 2D kagome weave 15 and a single-layer, surfacesupported, interwoven 2D polymer 16 have also been reported. However, despite being proposed on a number of occasions, [19][20][21][22][23] 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.

Bottom-up supramolecular assembly in two dimensions

“…Woven 2D assemblies have been recently developed by metal coordination of polycyclic monomers into pre-assembled tiles for intertwined 1D covalent polymerisation. 120,121 Other metal-organic suprapolymers can result in dynamic 2D assemblies, from woven to ordered complexes and randomly entangled networks. 122 Oligoproline monomers provide a metal-free and fully supramolecular alternative for 2D weaving based on p-p stacking of aromatic pendants at triaxial crossing points (Fig.…”

Magnetoelectrical Clothing Generator for High‐Performance Transduction from Biomechanical Energy to Electricity

“…Generally, triboelectric nanogenerators can result in high voltages yet relatively low current values due to the limitation of surface charge density. [1][2][3] Our magnetoelectrical clothing generator is based on electromagnetic induction, which is not subject to the restriction of surface charge density. Thus, we determined the maximum peak power density by using load resistors with different impedances (Figure 5c and Table S4, Supporting Information).…”

“…Clothing, as the second skin of humans, has been widely used to keep humans warm and deliver certain information. [1] In the last three decades, clothing has been endowed with diverse significant progress in this field, the magnets used above [1][2][3][4][5] are heavy and completely separated from the clothing. It is still challenging to combine rigid magnets and soft clothing together to facilitate a magnetoelectrical-type generator strategy.…”

Finite Assembly of Three‐Dimensional DNA Hierarchical Nanoarchitectures through Orthogonal and Directional Bonding

“…Life adopts self‐assembly to build things from simple to complex. Meanwhile, starting from basic elements such as small molecules, [1] polymers, [2] proteins [3] and colloidal particles, [4] artificially designed self‐assembly paves the way towards sophisticated nanoscale architectures and devices [5] . While hierarchical assembly is routine in living systems, assembling relatively large, complex and functional building blocks on demand is challenging, especially when finite assembly is desired.…”