Creation of Well-Defined “Mid-Sized” Micropores in Carbon Molecular Sieve Membranes
- Georgia Inst. of Technology, Atlanta, GA (United States)
Carbon molecular sieve (CMS) membranes are choices for the separation of organic molecules due to their stability, ability to be scaled at practical form factors, and the avoidance of expensive supports or complex multi-step fabrication processes. A critical challenge is the creation of “mid-range” (e.g., 5–9 Å) microstructures that allow for facile permeation of organic solvents and selection between similarly-sized guest molecules. In this work, we create these microstructures via the pyrolysis of a microporous polymer (PIM-1) under low concentrations of hydrogen gas. The introduction of H2 inhibits aromatization of the decomposing polymer and ultimately results in the creation of a well-defined bimodal pore network that exhibits an ultramicropore size of 5.1 Å. The H2 assisted CMS dense membranes show a dramatic increase in p-xylene ideal permeability (≈15 times), with little loss in p-xylene/o-xylene selectivity (18.8 vs. 25.0) when compared to PIM-1 membranes pyrolyzed under a pure argon atmosphere. This method is successfully extended to hollow fiber membranes operating in organic solvent reverse osmosis mode, highlighting the potential of this approach to be translated from the laboratory to the field.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA); ExxonMobil Research and Engineering
- Grant/Contract Number:
- AC52-07NA27344
- OSTI ID:
- 1566018
- Report Number(s):
- LLNL-JRNL-769201; 960479
- Journal Information:
- Angewandte Chemie (International Edition), Vol. 58, Issue 38; ISSN 1433-7851
- Publisher:
- WileyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Co-transport of water and p-xylene through carbon molecular sieve membranes
Flux Equations for Osmotically Moderated Sorption–Diffusion Transport in Rigid Microporous Membranes