Sorbate Transport in Carbon Molecular Sieve Membranes and FAU/EMT Intergrowth by Diffusion NMR

Abstract

In this paper we present and discuss selected results of our recent studies of sorbate self-diffusion in microporous materials. The main focus is given to transport properties of carbon molecular sieve (CMS) membranes as well as of the intergrowth of FAU-type and EMT-type zeolites. CMS membranes show promise for applications in separations of mixtures of small gas molecules, while FAU/EMT intergrowth can be used as an active and selective cracking catalyst. For both types of applications diffusion of guest molecules in the micropore networks of these materials is expected to play an important role. Diffusion studies were performed by a pulsed field gradient (PFG) NMR technique that combines advantages of high field (17.6 T) NMR and high magnetic field gradients (up to 30 T/m). This technique has been recently introduced at the University of Florida in collaboration with the National Magnet Lab. In addition to a more conventional proton PFG NMR, also carbon-13 PFG NMR was used.

Diffusion of Methane and Carbon Dioxide in Carbon Molecular Sieve Membranes by Multinuclear Pulsed Field Gradient NMR

“…16 In this work, we present a microscopic experimental investigation of carbon dioxide and methane self-diffusion in CMS membranes. Our preliminary results on methane selfdiffusion in CMS membranes are reported in ref 19. The studied CMS membranes have been derived from 6FDA/ BPDA(1:1)-DAM and Matrimid polymeric precursors.…”

A simple one‐step drop‐coating approach on fabrication of supported carbon molecular sieve membranes with high gas separation performance

“…Therefore, inorganic materials such as glasses, ceramics, silica, zeolites, metals, and carbon molecular sieves have come into consideration during the last several decades . Of them, carbon molecular sieve membranes (CMSMs) gained increasing attention due to the attractive characteristics, that is, thermal stability, corrosion resistance, and outstanding separation selectivity . More specially, CMSMs can efficiently separate the gas molecules with close diameters, such as H 2 , CO 2 , O 2 , N 2 , olefin, and paraffin .…”