Record Selectivity of SO ₂ by Molecularly Gated Sieving Membranes Having Cross‐Scale Mechanically Interlocked Nanofibers

Abstract

ABSTRACT 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 PM 0.3 with an ultralow pressure drop of 120 Pa, a record sulfur dioxide/nitrogen (SO 2 /N 2 ) selectivity of 37000, and a substantial SO 2 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.