Paralyzed membrane: Current-driven synthesis of a metal-organic framework with sharpened propene/propane separation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30410983.
- Also identified by DOI 10.1126/sciadv.aau1393 and PMC identifier 6218190.
- Licence recorded as CC BY-NC.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Metal-organic framework (MOF) membranes show great promise for propene/propane separation, yet a sharp molecular sieving has not been achieved due to their inherent linker mobility. Here, zeolitic imidazolate framework ZIF-8-type membranes with suppressed linker mobility are prepared by a fast current-driven synthesis (FCDS) strategy within 20 min, showing sharpened molecular sieving for propene/propane separation with a separation factor above 300. During membrane synthesis, the direct current promotes the metal ions and ligands to assemble into inborn-distorted and stiffer frameworks with ZIF-8_Cm (a newly discovered polymorph of ZIF-8) accounting for 60 to 70% of the membrane composition. Molecular dynamics simulations further verify that ZIF-8_Cm is superior to ZIF-8_I <math xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <mrow><mover><mn>4</mn> <mo>¯</mo></mover> <mn>3</mn> <mi>m</mi></mrow> </mrow> </math> (the common cubic phase) for propene/propane separation. FCDS holds great potential to produce high-quality, ultrathin MOF membranes on a large scale.