Dynamic Adaptive Two-Dimensional Supramolecular Assemblies for On-Demand Filtration

Abstract

Summary The construction of synthetic two-dimensional (2D) materials designates a pathway to the versatile chemical functionality by spatial control. However, current 2D materials with intelligence of stimuli-responsibility and adaptiveness have been unfledged. The approach reported here uses a supramolecular strategy to achieve the dynamic non-covalent self-assembly of a rationally designed small molecule monomer, producing large-area, ultra-thin, porous 2D supramolecular assemblies, which are solution-processable in aqueous solution. Importantly, the 2D supramolecular assemblies exhibit distinct adaptive capability to automatically regulate their network density and pore diameters in response to environmental temperature change, which could be developed into an "on-demand" filtration application for nanoparticles. Meanwhile, the 2D supramolecular assemblies can also perform reversible degradation/reformation by photo-irradiation. Our results not only show the simplicity, reliability, and effectiveness of supramolecular strategies in the construction of 2D materials with practical sizes, but also push the dynamic alterability and adaptation features from supramolecular assemblies toward 2D materials.

Stimuli-Responsive Two-Dimensional Supramolecular Polymers Based on Trinuclear Platinum(II) Scaffolds: Reversible Modulation of Photoluminescence, Cavity Size, and Water Permeability

“…In general, there are two strategies for creating stimuli-responsive gating membranes, including the expansion–contraction switching on pore sizes − and the hydrophilic–hydrophobic tunability of pore functions. , We consider the latter as the predominant effect in the present study. The 2D grazing-incidence X-ray diffraction (GIXRD) analysis (Figure S16) of the supramolecular membranes indicated that the hexagonal cavities within the 2D SPs always adopt an anisotropic orientation on the surfaces of the as-formed membranes before and after filtration, which leads to a relatively small change in cavity sizes that influences the pH-gating performance.…”

Bottom-up supramolecular assembly in two dimensions

“…Some other examples in this sense have been reported, with excellent enantiomeric separation (>99% ee). 126 Additionally, highly porous 2D assemblies can be used for the sizeselective ltration of nanoparticles, 96,127 where the thermal expansion of the pores can tune the size separation cut-off according to the pore distribution achieved. 96…”

“…Importantly, suppression of interlayer stacking can be achieved by incorporation of hydrophilic pendants into the planar scaffold. Refinement of this architectural concept aimed to release molecular strain to yield larger nanosheets, 95 provide stimuli-sensitivity 96 and attach specific fluorophores. 97 The use of semiflexible chains resulted in the generation of polymorphic 2D structures with lyotropic properties.…”

Driving Smart Molecular Systems by Artificial Molecular Machines

“…Polymers, representing an important platform for the combination of nanoscale chemistry and macroscopic objects, have been widely researched for potential applications in material science . The introduction of stimuli‐responsive molecular machine units into polymer systems to fabricate novel materials with advantageous properties such as self‐healability, high stretchability, and recyclability has drawn increased attention, while the introduction of responsive units may also endow these systems with controllable regulation …”