Gas Permeation through Mechanically Resistant Self‐Standing Membranes of a Neat Amorphous Organic Cage

• Published in: Chemistry : a European journal Vol. 29; no. 56; pp. e202301437 - n/a
• Main Authors: Mobili, Riccardo, La Cognata, Sonia, Monteleone, Marcello, Longo, Mariagiulia, Fuoco, Alessio, Serapian, Stefano A., Vigani, Barbara, Milanese, Chiara, Armentano, Donatella, Jansen, Johannes C., Amendola, Valeria
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 09.10.2023
• Subjects: Cages; Chemistry; Controllability; Crystals; Gas permeation; Gas transport; Membranes; Microporosity; molecular materials; organic cages; Permeation; Polyimide resins; Polymers; Single crystals; Thin films; Transport properties; membranes; organic cages; molecular materials; gas transport; thin films
• ISSN: 0947-6539; 1521-3765; 1521-3765
• DOI: 10.1002/chem.202301437

The synthesis and characterization of a novel film‐forming organic cage and of its smaller analogue are here described. While the small cage produced single crystals suitable for X‐ray diffraction studies, the large one was isolated as a dense film. Due to its remarkable film‐forming properties, this latter cage could be solution processed into transparent thin‐layer films and mechanically stable dense self‐standing membranes of controllable thickness. Thanks to these peculiar features, the membranes were also successfully tested for gas permeation, reporting a behavior similar to that found with stiff glassy polymers such as polymers of intrinsic microporosity or polyimides. Given the growing interest in the development of molecular‐based membranes, for example for separation technologies and functional coatings, the properties of this organic cage were investigated by thorough analysis of their structural, thermal, mechanical and gas transport properties, and by detailed atomistic simulations. Stand up and be tested: Self‐standing membranes of a neat organic cage are reported here. The cage membranes showed a remarkably good mechanical resistance, which made them suitable for gas‐permeation tests. This study pointed the possibility of using a simple organic cage molecule to achieve a molecular material with features that are generally observed with polymeric membranes.