Membrane materials, for gas separation

Ionic liquids have already been demonstrated to be effective membrane materials for gas separation when supported within a porous polymer support. However, supported ionic liquid membranes offer another versatile approach by which to perform two-phase catalysis. This technology combines some of the advantages of the ionic liquid as a catalyst solvent with the ruggedness of the ionic liquid-polymer gels. Transition metal complexes based on palladium or rhodium have been incorporated into gas-permeable polymer gels composed of [BMIM][PFg] and poly(vinyli-dene fluoride)-hexafluoropropylene copolymer and have been used to investigate the hydrogenation of propene [21]. 

Pis are attractive membrane materials for gas separation because of their good gas separation and physical properties. Many attempts have been made to modify the chemical structure of Pis in order to construct both highly permeable and permselective membrane materials. Blends of Pis have been demonstrated to exhibit improved performance in gas separation applications. ... 

Electronically conductive polyaniline has been paid much attention as a potential membrane material for gas separation because of high selectivity, particularly very high selectivity of oxygen over nitrogen (1-4), In addition, it is thermally stable and soluble in NMP, not like common electronically conductive polymers such as... 

On the one hand, linear aromatic polyimides have been generally used as electronic and aerospace materials because of their excellent mechanical strength, thermal, chemical and electronic/optic properties compared with other common amorphous polymers. Polyimides are also excellent membrane materials for gas separation due to their rigid chemical structures, allowing the production of larger functional free volume. Over the... 

A large number of polymers have been synthesized for various applications that depend on gas permeability, but in particular for potential uses as membrane materials for gas separation processes. The permeability of these polymers to various gases has been measured at different temperatures and in some cases over a range of pressures. The objective of this chapter is to complement and update the compilations of gas permeability data already published in Chapter 50 of the first edition of this Handbook. Since, due to limitations of space, it was not possible to Ust gas permeability data at all the various temperatures and pressures at which these data have been determined, and since different readers have different interests, only references to permeability data have been given. 

Fluorinated heterocyclic polyazoles due to their combination of high thermal and mechanical properties have been used as membrane materials for gas separation, pervaporation, and in fuel cell applications. 

Freeman [55] reported on nanostructured membrane materials for gas separation applications and presented examples where the incorporation of nanoscale particles into rigid polymers enhances the permeability and selectivity, for certain separations, based primarily on the disruption of the polymer chain packing by the nanoparticles (i.e., by altering diffusion selectivity of the polymer matrix). In addition, they discussed the incorporation into polymers of nanoparticles with specific interactions with particular gases (e.g., CO ) as a route to increase permeability and selectivity by altering the diffusion selectivity and solubility selectivity. 

The potential of SPPO as a membrane material for gas separation was first recognized in 1973 when Ward III and Salemme disclosed permeabilities of LMW SPPO-33.8 in various counter ion forms [3]. Percec and Li considered HSPPO as an intermediate material in formation of sulfonylated PPO products and reported its CO2 and CH permeabilities along with gas transport properties of other modified PPO polymers [8]. Bikson et al. focused on optimization of gas transport properties of LiSPPO by narrowing the molecular weight distribution of precursor PPO and by its homogeneous sulfonation [9]. Fu et al. studied the effect of DS on gas transport properties of LMW HSPPO and LMW NaSPPO [13]. Considering... 

Based on the above considerations effect of gold nanoparticles loading in polydimethyl siloxane matrix was examined for the separation of CO/CO2, CO/CH4 and CO2/CH4. The above gas mixtures are the product of syngas reaction and their separation is of great significance to industrial application in natural gas purification. PDMS have received considerable attention as potential membrane material for gas separation because of their high intrinsic permeability to gases and vapors. 

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