Ultrathin films of porous metal-organic polyhedra for gas separation.

Ultrathin films of a robust Rh-II-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/N-2 selectivity, demonstrating the great combined potential of MOP and Langmuir-based techniques in separation technologies.