Bioinspired Large-Area Polymeric Cucurbituril Monolayers with Ultrahigh-Density Nanopores Enabling Reversible Charge-Gating of Ion Transport via Host–Guest Recognition

Abstract

Achieving precise control over ion and molecular transport under subnanometer confinement, especially beyond passive sieving, remains challenging in nanofluidics and membrane science. Here, we present a bioinspired strategy that enables the formation of subnanometer channels together with the integration of tunable molecular recognition within 2D amorphous polymer membranes. Large-area membranes with a size up to 900 cm2 were fabricated by interfacial cross-linking of supramolecular assemblies. Molecular-level control over the amphiphilicity of cucurbituril host–guest complexes (HGCs) yields 1.6 nm thick amorphous monolayers with subnanometer pores at a high density of (1.5 ± 0.5) × 1013 cm–2, comparable to that of covalent organic frameworks (COFs). The nanopores formed between cucurbituril hosts serve as dense transport pathways, while the intrinsic cavities act as dynamic host–guest recognition sites. This architecture enables reversible charge-gating of ion transport via host–guest recognition and delivers outstanding performance in osmotic power generation. This work provides a design strategy for constructing adaptive transport systems, introducing dynamic functionality into otherwise static porous architectures, with potential applications for responsive separation and advanced energy harvesting.