Record Selectivity of SO2 by Molecularly Gated Sieving Membranes Having Cross-Scale Mechanically Interlocked Nanofibers.

Achieving selective molecular sieving, efficient particulate filtration, and passive signal acquisition into an integrated flexible membrane signifies a pivotal advancement toward interactive sensing-protective application. Herein, we unravel cross-scale mechanically interlocked poly(lactic acid) (CSMI-PLA) nanofibrous membranes fabricated via primary hydrogen bonding through polydopamine adhesion and secondary coordinate bonding via heterogeneous metal-organic frameworks entanglement. This hierarchically interlocked interface design establishes robust connectivity across dimensional scales, endowing CSMI-PLA with exceptional mechanical resilience and long-term sensing-protective durability. Remarkably, the CSMI-PLA membranes simultaneously achieve >99.45% removal of PM0.3 with an ultralow pressure drop of 120 Pa, a record sulfur dioxide/nitrogen (SO2/N2) selectivity of 37000, and a substantial SO2 uptake of 10.6 mmol·g- 1. Moreover, the CSMI-PLA membranes retain high functional integrity under multicomponent conditions while offering intrisical electroactivity that enables passive intelligent sensing. This work establishes a generalizable platform for engendering sensing-protective nanofibers, with promising implications for molecularly gated sieving and biodegradable self-adaptive wearables.