Metal Organic Framework-Polymer compatibility and gas separation performance

M. G. GARCÍA; N. A. OCHOA; L. PALACIO; P. PRÁDANOS; A. HERNANDEZ

Sitges

Conferencia; Fourth International Conference on Multifunctional, Hybrid and Nanomaterials (Hybrid Materials 2015) HYMA 2015; 2015

Elsevier

Most of the commercial gas separation membranes are polymeric in nature due to their economical fabrication, good mechanical properties and versatility of configurations such as hollow fibers and spirals modules. However, limitations in gas separation performance reached by pure polymers have promoted searching of new membrane designs that improve not only gas permeation but also gas separation performances. Surpassing Robeson ?trade off? of different gas pairs such as H2/CH4, CO2/CH4 and O2/N2 represents one of the major challenges to be reached. Metal Organic Frameworks (MOFs) are a relatively new class of hybrid materials built from metal ions as connectors and organic bridging ligands as linkers with the ability of selectively adsorbed gases. The combination of MOFs and polymers in the form of mixed matrix membranes (MMMs) has become an increasingly important field of research over the last few years due to the possibility of improving polymer-filler compatibility, preparing defect-free membranes and reaching better gas permselectivities. In this work, a new Nickel (II) metal organic framework and three commercial polymers were used to prepare mixed matrix membranes for gas separation. Compatibility between Ni-MOF and Matrimid, ULTEM 1000 and 6F6F polyimide was studied through optical microscopy, FTIR spectroscopy and XRD analysis. The influence of polymer-filler affinity was evaluated through gas permeation measurements. Ideal separation factors were calculated for H2/CH4 and CO2/CH4 gas pairs. Results showed Ni-MOF-polymer compatibility was in the order ULTEM 1000 > 6F6F > Matrimid. Charge transfer interaction between functional groups in polymers and Ni-MOF might be responsible for affinity. Gas separation results showed ULTEM 1000/Ni-MOF possess the highest H2/CH4 and CO2/CH4 selectivities.