title: Correlation of Gas Permeability in a Metal-Organic Framework MIL-101(Cr)-Polysulfone Mixed-Matrix Membrane with Free Volume Measurements by Positron Annihilation Lifetime Spectroscopy (PALS).
abstract: Hydrothermally stable particles of the metal-organic framework MIL-101(Cr) were incorporated into a polysulfone (PSF) matrix to produce mixed-matrix or composite membranes with excellent dispersion of MIL-101 particles and good adhesion within the polymer matrix. Pure gas (O2, N2, CO2 and CH4) permeation tests showed a significant increase of gas permeabilities of the mixed-matrix membranes without any loss in selectivity. Positron annihilation lifetime spectroscopy (PALS) indicated that the increased gas permeability is due to the free volume in the PSF polymer and the added large free volume inside the MIL-101 particles. The trend of the gas transport properties of the composite membranes could be reproduced by a Maxwell model.
authors: Institute of Inorganic and Structural Chemistry, Heinrich-Heine-University, 40204 Düsseldorf, Germany. harold.tanh.jeazet@uni-duesseldorf.de.
authors: Harold B Tanh
authors: HB
authors: Jeazet
authors: Institute for Materials Science, Faculty of engineering of the Christian-Albrechts-University, 24143 Kiel, Germany. tk@tf.uni-kiel.de.
authors: Tönjes
authors: T
authors: Koschine
authors: Institute of Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University, 40204 Düsseldorf, Germany. claudia.staudt@basf.com.
authors: Claudia
authors: C
authors: Staudt
authors: Institute for Materials Science, Faculty of engineering of the Christian-Albrechts-University, 24143 Kiel, Germany. kr@tf.uni-kiel.de.
authors: Klaus
authors: K
authors: Raetzke
authors: Institute of Inorganic and Structural Chemistry, Heinrich-Heine-University, 40204 Düsseldorf, Germany. janiak@uni-duesseldorf.de.
authors: Christoph
authors: C
authors: Janiak