Supported liquid membranes facilitating membrane structures

Yet another approach to stabilizing facilitated transport membranes is to form multilayer structures in which the supported liquid-selective membrane is encapsulated between thin layers of very permeable but nonselective dense polymer layers. The coating layers must be very permeable to avoid reducing the gas flux through the membrane materials such as silicone rubber or poly(trimethylsilox-ane) are usually used [26],... 

In these systems, the interface between two phases is located at the high-throughput membrane porous matrix level. Physicochemical, structural and geometrical properties of porous meso- and microporous membranes are exploited to facilitate mass transfer between two contacting immiscible phases, e.g., gas-liquid, vapor-liquid, liquid-liquid, liquid-supercritical fluid, etc., without dispersing one phase in the other (except for membrane emulsification, where two phases are contacted and then dispersed drop by drop one into another under precise controlled conditions). Separation depends primarily on phase equilibrium. Membrane-based absorbers and strippers, extractors and back extractors, supported gas membrane-based processes and osmotic distillation are examples of such processes that have already been in some cases commercialized. Membrane distillation, membrane... 

A novel polymeric bicontinuous microemulsion (PBM) membrane, consisting of an interconnecting network of nanometer pore size water channels, was employed as liquid membrane support [13] for the immobilization of new porphyrin carrier [14] for facilitated oxygen transport. Although the membrane resulted to be stable due to the nanoporous structure, a modest (2.3-2.4) O2/N2 selectivity was achieved. 

In this study, experiments on the simultaneous permeation of CO2 and CH4 through aqueous MEA, DEA and ethylenediamine hydrochloride (EDAHCl) membranes are performed and the permeation rates of CO2 are quantitatively discussed on the basis of the approximate solution of facilitated transport (77). A method is also proposed for applying the facilitated transport theory developed for a liquid membrane consisting of a liquid membrane phase alone to the analysis of facilitated transport through a supported liquid membrane prepared by impregnating a microporous polymer support having tortuous pore structure with a carrier solution. 

In Section 5.4.4, we studied a variety of chemical reaction facilitated separation where the reaction was taking place in a thin liquid layer acting as the liquid membrane Figure 5.4.4 illustrated a variety of liquid membrane permeation mechnisms. Here we will identify first the structural configuration of the liquid membranes as they are used in separators with countercurrent flow pattern (as well as for the cocurrent flow pattern). There are three general classes of liquid membrane structures emulsion liquid membrane (ELM) supported liquid membrane (SLM) or immobilized liquid membrane (ILM) hollow fiber contained liquid membrane (HFCLM). Each will be described very briefly. 

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