Structured supported ionic liquid-phase

SSILP structured supported ionic liquid phase... 

Structured supported ionic liquid-phase (SSILP) catalysis is a new concept that combines the advantages of ionic liquids (ILs) as solvents for homogeneous catalysts with the benefits of structured solid catalysts. In an attempt to prepare a homogeneous IL film on a microstructured support, SMFs were coated by a layer of carbon nanofibers as described above. An IL thin film was then immobilized on the CNF/SMF support. The high interfacial area of the IL film enabled the efficient use of a transition metal catalyst for the selective gas-phase hydrogenation of acetylenic compounds [267,268]. 

M. Ruta, I. Yuranov, P.J. Dyson, G. Laurenczy, L. Kiwi-Minsker, Structured fiber supports for ionic liquid-phase catalysis used in gas-phase continuous hydrogenation, J. Catal. 247 (2007) 269. 

Silica surfaces with lower surface charge are distinctly different from mica surfaces and are usually of greater importance in catalytic processes where they constitute the primary support material in supported ionic Hquid phase (SILP) catalysis. The structural arrangement of ionic liquid studied by surface analytical techniques, UHV techniques, in particular, point toward preferential cation enrichment at the innermost surface layers. 

These types of separators consist of a solid matrix and a liquid phase, which is retained in the microporous structure by capillary forces. To be effective for batteries, the liquid in the microporous separator, which generally contains an organic phase, must be insoluble in the electrolyte, chemically stable, and still provide adequate ionic conductivity. Several types of polymers, such as polypropylene, polysulfone, poly(tetrafluoroethylene), and cellulose acetate, have been used for porous substrates for supported-liquid membranes. The PVdF coated polyolefin-based microporous membranes used in gel—polymer lithium-ion battery fall into this category. Gel polymer... 

Way, Noble and Bateman (49) review the historical development of immobilized liquid membranes and propose a number of structural and chemical guidelines for the selection of support materials. Structural factors to be considered include membrane geometry (to maximize surface area per unit volume), membrane thickness (<100 pm), porosity (>50 volume Z), mean pore size (<0.1)jm), pore size distribution (narrow) and tortuosity. The amount of liquid membrane phase available for transport In a membrane module Is proportional to membrane porosity, thickness and geometry. The length of the diffusion path, and therefore membrane productivity, is directly related to membrane thickness and tortuosity. The maximum operating pressure Is directly related to the minimum pore size and the ability of the liquid phase to wet the polymeric support material. Chemically the support must be Inert to all of the liquids which It encounters. Of course, final support selection also depends on the physical state of the mixture to be separated (liquid or gas), the chemical nature of the components to be separated (inert, ionic, polar, dispersive, etc.) as well as the operating conditions of the separation process (temperature and pressure). The discussions in this chapter by Way, Noble and Bateman should be applicable the development of immobilized or supported gas membranes (50). 

SLM usually is the progressive loss of the liquid embedded in the membrane into the surrounding phases due to liquid vaporization, dissolution into the adjacent liquid phases and/or shifting from the porous structure of the supported membrane under low-pressure gradients [2]. The use of ionic liquids as liquid phase could overcome these inconveniences due to their unique properties [3-5]. Ionic... 

The most efficient catalysts in liquid-phase oxidation of organic compoimds were crystalline mked oxides [1]. They are ionic mixed oxides or mixed oxides containing oxides supported on oxides. In the latter case, the catalytic activity of the oxide support is increased by adding one or more metal components or is obtained by immobilization of metal oxides on inactive oxide support. Metal ions were isomorphously substituted in framework positions of molecular sieves, for example, zeolites, silicalites, silica, aluminosilicate, aluminophosphates, silico-aluminophosphates, and so on, via hydrothermal synthesis or postsynthesis modification. Among these many mixed oxides with crystalline microporous or mesoporous structure, perovskites were also used as catalysts in liquid-phase oxidation. 

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