Ultrathin Films of Porous Metal–Organic Polyhedra for Gas Separation

Ultrathin films of a robust RhII -based porous metal-organic polyhedra (MOP) have been obtained. Homogeneous and compact monolayer films (ca. 2.5 nm thick) were first formed at the air-water interface, deposited onto different substrates and characterized using spectroscopic methods, scanning transmission electron microscopy and atomic force microscopy. As a proof of concept, the gas separation performance of MOP-supported membranes has also been evaluated. Selective MOP ultrathin films (thickness ca. 60 nm) exhibit remarkable CO₂ permeance and CO₂ /N₂ selectivity, demonstrating the great combined potential of MOP and Langmuir-based techniques in separation technologies.