title: Investigation of cross-linked and additive containing polymer materials for membranes with improved performance in pervaporation and gas separation.
abstract: Pervaporation and gas separation performances of polymer membranes can be improved by crosslinking or addition of metal-organic frameworks (MOFs). Crosslinked copolyimide membranes show higher plasticization resistance and no significant loss in selectivity compared to non-crosslinked membranes when exposed to mixtures of CO2/CH4 or toluene/cyclohexane. Covalently crosslinked membranes reveal better separation performances than ionically crosslinked systems. Covalent interlacing with 3-hydroxypropyldimethylmaleimide as photocrosslinker can be investigated in situ in solution as well as in films, using transient UV/Vis and FTIR spectroscopy. The photocrosslinking yield can be determined from the FTIR-spectra. It is restricted by the stiﬀness of the copolyimide backbone, which inhibits the photoreaction due to spatial separation of the crosslinker side chains. Mixed-matrix membranes (MMMs) with MOFs as additives (fillers) have increased permeabilities and often also selectivities compared to the pure polymer. Incorporation of MOFs into polysulfone and Matrimid® polymers for MMMs gives defect-free membranes with performances similar to the best polymer membranes for gas mixtures, such as O2/N2 H2/CH4, CO2/CH4, H2/CO2, CH4/N2 and CO2/N2 (preferentially permeating gas is named first). The MOF porosity, its particle size and content in the MMM are factors to influence the permeability and the separation performance of the membranes.
authors: Institute of Physical Chemistry, Heinrich-Heine-University, Düsseldorf 40225, Germany. katharina.hunger@hhu.de.
authors: Katharina
authors: K
authors: Hunger
authors: Institute of Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University, Düsseldorf 40225, Germany. nadine.schmeling@uni-duesseldorf.de.
authors: Nadine
authors: N
authors: Schmeling
authors: Institute of Inorganic and Structural Chemistry, Heinrich-Heine-University, Düsseldorf 40225, Germany. harold.tanh.jeazet@uni-duesseldorf.de.
authors: Harold B Tanh
authors: HB
authors: Jeazet
authors: Institute of Inorganic and Structural Chemistry, Heinrich-Heine-University, Düsseldorf 40225, Germany. janiak@uni-duesseldorf.de.
authors: Christoph
authors: C
authors: Janiak
authors: Institute of Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University, Düsseldorf 40225, Germany. claudia.staudt@basf.com.
authors: Claudia
authors: C
authors: Staudt
authors: Institute of Physical Chemistry, Heinrich-Heine-University, Düsseldorf 40225, Germany. kleinermanns@uni-duesseldorf.de.
authors: Karl
authors: K
authors: Kleinermanns