New Generation of Mixed Matrix Membranes for Targeted Gas Separation
11:30 - 12:00
The major issue for development of new separation membranes is achieving a high selectivity towards the target gas. Polymer-based mixed matrix polymer membranes (MMMs) containing nano-scale additives are seen as a promising candidates to achieve a radical improvement in gas separation. Nevertheless, these materials very often suffer from insufficient control of the nano-level phenomena such as poor dispersion of the additives, low compatibility with the matrix, deterioration of mechanical properties that causes unwanted defects, voids, non-uniform distribution or aggregation of nano-particles in polymer matrix etc. Therefore, preparation of new sophisticated membrane materials with improved performance, i.e. enhanced permeability and/or selectivity requires new ideas and approaches. In this work, an innovative approach of the ex-situ controlled embedding of tailor-made tunable additives into highly branched polyimide-based MMMs is presented. Nano- and sub-micron additives based on zeolite-imidazole frameworks (ZIF-8), iron oxide nanoparticles and surface-modified SiO2 hollow spheres were embedded using unique custom-made device with controlled magnetic-field.
The performance of MMMs based on 4,4'-oxydiphthalic anhydride with 4,4',4''-triaminotriphenyle-methane and 4,4' (hexa-fluorisopropylidene)diphtalic-anhydride with 4,4',4''-triaminotriphenyle-methane were tested via gravimetric and time-lag fixed volume pressure increase methods. Determined results for carbon dioxide, methane and other gases show very promising properties (permeability/selectivity) in corresponding 2008 Robeson plots.