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Solid polymer layer

The solid polymer layer In this layer, the solid, polymer-rich phase undergoes continuous desolvation, and the system composition changes from D to B. It is the shrinkage or syneresis of the solid polymer accompanying this composition change that produces stresses in the polymer. Because the polymer is solid, these stresses cannot be as easily relieved by bulk movement of polymer as in the fluid polymer layer. Instead, the polymer... [Pg.185]

When a polymer powder material is brought into contact with metal ware heated above the polymer melting point, the processes of deposition, holding powder particles on the ware surface and formation of a solid polymer layer can be joined together. [Pg.206]

Later Thevenin and Muller suggested several modifications to the SEI model (1) the polymer-electrolyte interphase (PEI) model in which the lithium in PC electrolyte is covered with a PEI composed of a mixture of LijCOj, P(PO),and LiClO, P(PO), is polypropylene oxide, formed by reduction-induced polymerization of PC (2) the solid-polymer-layer (SPL) model, where the surface layer is assumed to consist of solid compounds dispersed in the polymer electrolyte (3) the compact-stratified layer (CSL) — in this model the surface layer is assumed to be made of two sublayers. The first layer on the electrode surface is the SEI, while the second layer is either SEI or PEI. The first two... [Pg.6]

The manufacture of base discs for laser recording material is realized by covering of the plastic substrates surface with solid polymer layer possessing directing channels and/or signal holes. The surface of the plastic substrate is preliminary cleaned by UV/ozone exposure before the formation of the hardened polymer layer [128],... [Pg.141]

Ishikawa, M., Morita, M., lhara, M. and Matsuda, Y., Electric double layer capacitor composed of activated carbon fiber cloth electrodes and solid polymer electrolytes containing alkylammonium salt, J. Electrochem. Soc., 1994, 141(7), 1730 1734. [Pg.118]

Nous s. solid polymer, aq, aqueous solution, gel. expanded polymergel m, meul electrode, dif. diffusion layer, solv, solvated molecules or ions... [Pg.340]

To keep the consumption of the valuable platinum low, thin foils have been glued to a graphite support [34] or thin-layers of platinum have been sputtered on to a glass base [59]. Platinum can be used in a particle electrode by plating silica gel with platinum [60], or in a solid polymer electrolyte where platinum is incorporated into a nafion ion exchange membrane [61]. [Pg.95]

Incorporation into a Polymer Layer In recent years a new electrode type is investigated which represents a layer of conducting polymer (such as polyaniline) into which a metal catalyst is incorporated by chemical or electrochemical deposition. In some cases the specific catalytic activity of the platinum crystallites incorporated into the polymer layer was found to be higher than that of ordinary dispersed platinum, probably because of special structural features of the platinum crystallites produced within the polymer matrix. A variant of this approach is that of incorporating the disperse catalyst directly into the surface layer of a solid polymer electrolyte. [Pg.536]

The observed distribution can be readily explained upon assuming that the only part of polymer framework accessible to the metal precursor was the layer of swollen polymer beneath the pore surface. UCP 118 was meta-lated with a solution of [Pd(AcO)2] in THF/water (2/1) and palladium(II) was subsequently reduced with a solution of NaBH4 in ethanol. In the chemisorption experiment, saturation of the metal surface was achieved at a CO/Pd molar ratio as low as 0.02. For sake of comparison, a Pd/Si02 material (1.2% w/w) was exposed to CO under the same conditions and saturation was achieved at a CO/Pd molar ratio around 0.5. These observations clearly demonstrate that whereas palladium(II) is accessible to the reactant under solid-liquid conditions, when a swollen polymer layer forms beneath the pore surface, this is not true for palladium metal under gas-solid conditions, when swelling of the pore walls does not occur. In spite of this, it was reported that the treatment of dry resins containing immobilized metal precursors [92,85] with dihydrogen gas is an effective way to produce pol-5mer-supported metal nanoclusters. This could be the consequence of the small size of H2 molecules, which... [Pg.211]

Significant advances have been made in this decade in electrochemical H2 separation, mostly through the use of solid polymer electrolytes. Since the overpotentials for H2 reduction and oxidation are extremely low at properly constructed gas diffusion electrodes, very high current densities are achievable at low total polarization. Sedlak [13] plated thin layer of Pt directly on Nafion proton conductors 0.1-0.2cm in thickness, and obtained nearly 1200 mA/cm2 at less than 0.3 V. The... [Pg.208]

A solid suspended in a solid is called a solid suspension. Pigmented plastic - particles of dye suspended in a solid polymer - is a simple example. Freezing a liquid-liquid emulsion, such as milk, also yields a solid suspension. A layer of partially set paint, in which the urethane monomer has been consumed but the polymer has yet to form long chains, can also be thought of as representing a solid suspension. [Pg.507]

Model of Dissolution. Based on the results described above, a model for the dissolution of phenolic resins in aqueous alkali solutions 1s proposed. The model 1s adapted from Ueberrelter s description for polymer dissolution 1n organic solvents (.21). In Ueberrelter s model, the dissolution process takes place 1n several steps with the formation of (a) a liquid layer containing the dissolved polymer, (b) a gel layer, (c) a solid swollen layer, (d) an infiltration layer, and (e) the unattacked polymer. The critical step which controls the dissolution process is the gel layer. In adapting h1s model to our case, we need to take into account the dependence of solvation on phenolate ion formation. There 1s a partition of the cation and the hydroxide ion between the aqueous solution and the solid phase. The... [Pg.378]

Several approaches towards monolithic GC columns based on open pore foams prepared in large diameter glass tubes were reported in the early 1970s [26,27, 110]. However, these columns had poor efficiencies, and the foams possessed only limited sample capacities in the gas-solid GC mode. Subsequent experiments with polymerized polymer layer open tubular (PLOT) columns where the capillary had completely been filled with the polymer were assumed to be failures since the resulting stationary phase did not allow the gaseous mobile phase to flow [111]. [Pg.106]

Note that migration is important for ionic movement within solid polymer electrolytes or solid-state electrtxthromic layers since the transport numbers of the electroactive species or of the mobile counterions become appreciable. These a.spects are unlikely to trouble us further in this present text. [Pg.21]

M. Neergat and A. K. Shukla. Effect of diffusion-layer morphology on the performance of solid-polymer-electrolyte direct methanol fuel cells. Journal of Power Sources 104 (2002) 289-294. [Pg.294]


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See also in sourсe #XX -- [ Pg.30 ]

See also in sourсe #XX -- [ Pg.444 ]




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Layered solids

Polymer layers

Solid layer

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