Airflow‐Field‐Induced Sandwich‐Type Membrane of Block Copolymer for Selective Ion Separation

However, the broad size distribution and the low density of nanostructures for such membranes still pose major problems to the preparation of separation membranes with high performance. Nanostructured block copolymer (BCP) fi lm based on microphase separation may offer a solution, [ 5 ] as the separated phase in BCP fi lm provides the diffusion channels for chemical species. By far, BCP fi lm with various nanostructures such as vertical nanocylinders across the entire fi lm and bicontinuous microdomains have been reported. [ 6 ]