Porous dispersion technology

A typical embodiment for the porous layer technology is described in several patents and patent applications, e.g., a US patent application in 2006. This patent application describes a method for the preparation of silicon dioxide dispersions wherein the surface of the silicon dioxide is modified by treatment with the reaction products of a compound of trivalent aluminum with amino-organo-silane. The invention relates to recording sheets for inkjet printing having such a dispersion incorporated in the porous inkreceiving layer. Another US patent describes the preparation of nanoporous alumina oxide or hydroxide which contains at least one element of the rare earth metal series with atomic numbers 57 to 71. 

Through these processes dissolved substances and/or finely dispersed particles can be separated from liquids. All five technologies rely on membrane transport, the passage of solutes or solvents through thin, porous polymeric membranes. 

The typical solid catalyst used in technology consists of small catalytically active species, such as particles of metal, metal oxide, or metal sulfide, dispersed on a low-cost, high-area, nearly inert porous support such as a metal oxide or zeolite. The catalytic species are typically difficult to characterize in-... 

A variety of industrial catalytic processes employ small metal-particle catalysts on porous inorganic supports. The particle sizes are increasingly in the nanometre size range which gives rise to nanocatalysts. As described in chapter 1, commonly used supports are ceramic oxides, like alumina and silica, or carbon. Metal (or metallic) catalysts in catalytic technologies contain a high dispersion of nanoscopic metal particles on ceramic oxide or carbon supports. This is to maximize the surface area with a minimum amount of metal for catalytic reactions. It is desirable to have all of the metal exposed to reactants. 

It should be noted that the field tests were made with only one type of surfactant, and without benefit of many recent research advances in such areas as high-pressure phase behavior and surfactant design, mechanisms of dispersion formation and disappearance, and mechanisms of dispersion flow through porous media. Furthermore, the design and successful performance of field tests pose many technological challenges in addition to those encountered in the prerequisite experimental and theoretical research. 

In Section 5.3 it was demonstrated with many examples that ionic hquids are indeed a very attractive class of solvents for catalysis in liquid-liquid biphasic operation (for some selected reviews see Refs. [16-20]). In this section, we wfll focus on a different way to apply ionic liquids in catalysis, namely the use of an ionic liquid catalyst phase supported on a solid carrier, a technology that has become known as supported ionic liquid phase (SILP) catalysis. In comparison to the conventional liquid-liquid biphasic catalysis in ionic liquid-organic liquid mixtures, the concept of SILP-catalysis combines well-defined catalyst complexes, nonvolatile ionic liquids, and porous solid supports in a manner that offers a very efficient use of the ionic liquid catalyst phase, since it is dispersed as a thin film on the surface of the high-area support. Recently, the initial applications using such supported ionic liquid catalysts have been briefly summarized [21]. In contrast to this report, where the applications were distinguished by the choice of support material, the compilation here will divide the applications using the supported ionic liquid catalysts into sections according to the nature of the interaction between the ionic liquid catalyst phase and the support. 

In the past few decades the technological possibilities and interests have boosted research in systems in highly restricted geometries in almost every field of physics — recently down to lengthscales close to or even below the molecular level. In the field of liquid crystals, the importance of electro-optical applications which incorporate ordered liquid materials [1-3] has focused the research on LC systems with high surface-to-volume ratio [4]. In order to provide mechanically stable applications, liquid crystals are dispersed in polymers, stabilized by a polymer network, fill the cavities in porous materials, etc. [5,6]. The major technological interest concerns the scattering, reflective and bistable displays, optical switches, and others. 

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