Macro porous

Ceramic honeycomb monoliths are porous macro-structured supports consisting of parallel channels. On the walls a thin layer of active material can be applied (Figure 1). Honeycomb catalyst supports were originally developed for use in automotive... 

Because of the attractive physicochemical properties and potential applications in catalysis, biotechnology, adsorption, and separation, fabrication of hierarchically porous (macro/mesoporous) materials, especially for the three-dimensional ordered macro/ mesoporous (3DOM) materials, has been a focus in the research on materials science and engineering in recent years [99,199,200], By using close-packed arrays of monodisperse spheres, such as polystyrene (PS), poly(methyl methacrylate) (PMMA), and silica as template, metals [201,202], metal oxides [203-208], metal chalcogenides [209], silica [204,210,211], carbon [212,213], polymers [214,215], and hydroxyapatite [216] with 3DOM structures have been generated. 

Another potential risk is the introduction of a limit value in the soot particles number (for example the limit could be fixed at 1011 particles/km). This new limitation could have a consequence on the DPF filtering medium. In such a context, the DPF technology with macro porous open medium will not be relevant any more. 

Isshiki and Nakayama [234] have discussed the selective concentration of cobalt in seawater by complexation with various ligands or sorption on macro-porous X AD resins. Complexed cobalt is collected after passage through a small XAD resin-packed column. 

A lateral variation of the anodization current will produce different growth rates and consequently an interface roughness for porous layers. Note that this is not the case for stable macro PS formation on n-type, because here the growth rate is independent of current density. An inhomogeneous current distribution at the O-ring seal of an anodization cell or at masked substrates produces PS layer thickness variations, as shown in Fig. 6.6. Inhomogeneities of the current distribution become more pronounced for low doped substrates, as shown in Figs. 6.3 b and 6.5 d [Kr3]. 

The catalyst layer is composed of multiple components, primarily Nafion ion-omer and carbon-supported catalyst particles. The composition governs the macro- and mesostructures of the CL, which in turn have a significant influence on the effective properties of the CL and consequently the overall fuel cell performance. There is a trade-off between ionomer and catalyst loadings for optimum performance. For example, increased Nafion ionomer confenf can improve proton conduction, but the porous channels for reactanf gas fransfer and water removal are reduced. On the other hand, increased Pt loading can enhance the electrochemical reaction rate, and also increase the catalyst layer thickness. 

Fig. 1.8 Schematic representation of A) gei-type, B) branched gei-type, C) macro-porous and D) branched macroporous resins.

Still following the macro-structural hypothesis which we favored at that time, we abondoned the idea of a specific favorable influence of flux promoters and assumed instead that the cause for the success of the magnetite experiment was the compact porous structure of the iron sponge which was formed in the test oven by the reduction of the Swedish ore. An apparent support of this idea was that contrary to the favorable action of the dense iron sponge obtained from magnetite, catalysts of a looser structure such as, e.g., iron asbestos preparations had always been particularly ineffective. 

The result of all these experiments was that the idea of a particularly beneficial macro-compact porous state of the catalyst had to be abandoned, although patents had already been filed in which this had been claimed. Instead, we returned still more convinced of its correctness, to the previous more general hypothesis of the desirability of multi-component catalysts. 

Shea KJ, Stoddard GJ, Shavelle DM, Wakui F, Choate RM. Synthesis and characterization of highly cross-linked polyacrylamides and polymethacrylamides—a new class of macro-porous polyamides. Macromolecules 1990 23 4497-4507. 

Synthetic or semi-synthetic porous sheets, so-called membranes, able to bind proteins and other macromolecules non-specifically and with high capacity (amount of bound macro-Blotting supports molecules per area), are mostly used as materials for planar blotting... 

Kay P., P.A. Blackwell, and A.B.A. Boxall (2004). Pate of veterinary antibiotics in a macro-porous tile drained clay soil. Environmental Toxicology and Chemistry 23 1136-1144. Keller B.J., H. Yamanaka, and R.G. Thurman (1992). Inhibition of mitochondrial respiration and oxygen-dependent hepatoxicity by six structurally dissimilar peroxisomal proliferating agents. Toxicology 71 49-61. 

T0025 Akzo Nobel MPP Systems, Macro Porous Polymer (MPP)... 

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