By WU Lixin's Group

Consecutive two-dimensional frameworks in large area represent ideal membranes for sieving molecules and/or nano-objects, but challenges still remain in methodology and practical preparation. Prof. Wu’s group focus their research on exploiting new methodologies to create the self-assemblies with specified structures targeting useful applications in nanoscience in the past decade.

Recently, his group developed a novel method to build soft single-layer ionic organic–inorganic frameworks via electrostatic interaction. The selected polyanionic clusters serving as binding node and cationic pseudorotaxanes acting as bridging group are co-assembled to form a single-layer ionic framework with ca. 1.4 nm layer thickness. Such soft supramolecular polymer frameworks possess uniform and adjustable ortho-tetragonal nanopores in pore size of 3.4–4.1 nm. The membranes prepared from the framework assemblies exhibit greatly convenient solution processability and demonstrate a precisely size-selective separation of semiconductor quantum dots within ca. 0.1 nm of accuracy. The results hold promise in selective transport, molecular separation and dialysis systems. (Nat. Commun., 2016, 7, 10742.)