%0 Journal Article %T Correlation of Gas Permeability in a Metal-Organic Framework MIL-101(Cr)¨CPolysulfone Mixed-Matrix Membrane with Free Volume Measurements by Positron Annihilation Lifetime Spectroscopy (PALS) %A Harold B. Tanh Jeazet %A T£¿njes Koschine %A Claudia Staudt %A Klaus Raetzke %A Christoph Janiak %J Membranes %D 2013 %I MDPI AG %R 10.3390/membranes3040331 %X 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 (O 2, N 2, CO 2 and CH 4) 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. %K gas separation %K membranes %K permeability %K permselectivity %K mixed-matrix membranes %K metal-organic frameworks (MOFs) %K porosity %K PALS %U http://www.mdpi.com/2077-0375/3/4/331