Oxide Membranes

Cuprous oxide membrane Cryslalline cuprous oxide Cuprous chloride... 

The principal cathodic reaction on the upper surface of the membrane is the reduction of Cu " that is formed by the reaction of Cu with dissolved oxygen in the water these Cu ions are provided partly from the diffusion through the pores in the oxide membrane from within the pit and partly from those produced by cathodic reduction (equation 1.154). Lucey s theory thus rejects the conventional large cathode small anode relationship that is invoked to explain localised attack, and this concept of an electronically conducting membrane has also been used by Evans to explain localised attack on steel due to a discontinuous film of magnetite. 

D. Eng, and M. Stoukides, Catalytic and Electrocatalytic Methane Oxidation with Solid Oxide Membranes, Catalysis Reviews - Science and Engineering 33, 375-412 (1991). 

Basically, three kinds of membranes are being studied inorganic oxide membranes, polymer-based membranes, and metal and metal alloy membranes. Some combinations of these are also used, such as impregnating inorganic oxide membranes with catalytic materials. A key term in this held is permselective membrane, which is a thin material that can allow a certain component of a mixture, but not other components, to pass through (or permeate) from one side to the other. 

Fig. 3. Oxygen transport in solids. 02 is dissociated and ionized at the reduction interface to give O2 ions, which are transferred across the solid to the oxidation interface, at which they lose the electrons to return back to 02 molecules that are released to the stream, (a) In the solid electrolyte cell based on a classical solid electrolyte, the ionic oxygen transport requires electrodes and external circuitry to transfer the electrons from the oxidation interface to the reduction interface (b) in the mixed conducting oxide membrane, the ionic oxygen transport does not require electrodes and external circuitry to transfer the electrons to the reduction interface from the oxidation interface, because the mixed conductor oxide provides high conductivities for both oxygen ions and electrons.

Direct fluorination of polymer or polymer membrane surfaces creates a thin layer of partially fluorinated material on the polymer surface. This procedure dramatically changes the permeation rate of gas molecules through polymers. Several publications in collaboration with Professor D. R. Paul62-66 have investigated the gas permeabilities of surface fluorination of low-density polyethylene, polysulfone, poly(4-methyl-1 -pentene), and poly(phenylene oxide) membranes. 

Figure 2.14. The structure of an anodized aluminum oxide membrane (Anopore) as shown in Anotec Separations (1986) (a) is a homogeneous membrane (b) an asymmetric membrane.

Figure 2.16. Production scheme of a anodic aluminum oxide membrane (Smith 1973,1974).

Frcilich, D. and G. B. Tanny. 1978. The formation mechanism of dynamic hydrous Zr (IV) oxide membranes on microporous supports. J. Coll. Interface Sci. 64(2) 362-70. 

Mitrovic, M. and L. Knezic. 1979. Electrolytic aluminum oxide membranes -a new kind of membrane with reverse osmosis characteristics. Desalination 28 147-56. 

Smith, A. W. 1973. Porous anodic aluminum oxide membrane. J. Electrochem. Soc. 120(8) 1068-69. 

Konno, M., M. Shindo, S. Sugawara and S. Saito. 1988. A composite palladium and porous aluminum oxide membrane for hydrogen gas separation, J. Membr, Sci. 37 193-97. 

Fumeaux, R. C., A. P. Davidson and M. D. Ball. 1987. Porous anodic aluminum oxide membrane catalyst support. European Patent Appl. 0,244,970A1. 

Figure 12. Burst strength of oxidized membrane that was soaked in NaClO of...

By contrast, Nal-doped polyethylene oxide membranes have permitted experimental research on tiny rechargeable Na/l2 batteries to be initiated (Figure 2). Chemical stability of the electrolyte, and the integrity of the mechanical contacts at the current collector/electrolyte interfaces, during repetitive cycling, must be improved. 

Porous aluminium oxide membranes Au 0.26 pm diameter and 0.3-pm- to 3.0-pm-long gold particles were formed in the pores of aluminium oxide membranes 491... 

W.H. Jo, H.J. Kim, Y.S. Kang, Separation of water—ethanol mixture through poly(acrylonitrile-co-acrylic acid)/poly(ethylene oxide) membranes by pervaporation, J. Appl. Polym. Sci. 51 (1994) 529— 535. 

Car A, Stropnik C, Yave W et al (2008) PEG modified poly(amide-b-ethylene oxide) membranes for C02 separation. J Membr Sci 307(l) 88-95... 

Lin, Y. S., Wang, W., and Han, J. (1994). Oxygen permeation through thin mixed-conducting solid oxide membranes, AIChE J. 40(5), 786. 

In this regard, hydrogen flux by proton transport in a dense oxide membrane, in the short circuit case, is described by the ambipolar diffusion expression (see Figure 10.3a) [40,48,49]... 

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