Characterization of Inorganic Membranes

M.G. Liu, R. Ben Aim and M. Mietton Peuchot, Characterization of inorganic membranes by permporometry method importance of non equilibrium phenomena, in A.J. Burggraaf, J. Charpin and L. Cot (Eds.), Inorganic Membranes. Key Engineering Materials 61 62, Trans Tech Publications, Zurich, 1991, pp. 603-605. 

The preparation and fabrication methods and their conditions described in Chapter 3 dictate the general characteristics of the membranes produced which, in turn, affect their performance as separators or reactors. Physical, chemical and surface properties of inorganic membranes will be described in detail without going into discussions on specific applications which will be treated in later chapters. Therefore, much of this chapter is devoted to characterization techniques and the general characteristics data that they generate. 

Membrane morphology and, in the case of porous membranes, pore size and orientation and porosity are vital to the separation properties of inorganic membranes. As the general characterization techniques evolve, the understanding of these miciostnictures improves. 

The inorganic membrane reactor technology is in a state characterized by very few in practice but many of promise. Since the potential payoff of this technology is enormous, it deserves a close-up look. This and the following three chapters are, therefore, devoted to the review and summary of the various aspects of inorganic membrane reactors applications, material, catalytic and engineering issues. 

C.L. Lin, D.L. Flowers and P.K.T. Liu, Characterization of ceramic membranes. II. Modified commercial membranes with pore size imder 40 A. /. Membr. Sci., 92 (1994) 45. J. Luyten, J. Cooymans, R. Persons, R. Leysen and J. Sleurs, A New Ceramic Support Material for Gas Separative Membranes. Paper presented at the 3rd International Conference on Inorganic Membranes, July, 1994, Worcester, MA, USA. 

S. Xiang and Y.H. Ma, Formation and characterization of zeolite membranes from sols. Paper presented at the 3rd International Coivference on Inorganic Membranes, July 10-14,1994, Worcester, MA, USA. 

H. P. Hsieh, General characteristics of inorganic membranes, in Inorganic Membranes Characterization and Applications, R.R. Bhave (Ed.), van Nostrand Reinhold, New York, 1991. 

Inorganic membranes are made of inorganic materials such as metals, ceramics, zeolites, glasses, carbon, and so on. Actually, inorganic membranes usually consist of several layers from one or more different inorganic materials. Details of inorganic membranes with respect to their syntheses, characterizations, transport theories, and scaling-up problems have been well reviewed and summarized by several authors [5,6]. 

From this brief historical perspective, it can be seen that metal oxides were the basis of inorganic membrane development. In this chapter we will try to examine, in a tutorial rather than complex form, the main features of the metal oxide based membranes, as an important part of the field of inorganic membranes. In this way, some paragraphs will be initially devoted to the fundamentals of membrane synthesis, covering the most common membrane making techniques. Structural, fimctional, and electrical membrane characterization methods will then be introduced. Finally, we... 

Inorganic membranes, such as purely molecular sieving zeohte membranes, carbon membranes, " alumina membranes," and silica membranes," have high thermal and chemical stabUities. Over the past 25 years, extensive work has been reported on the synthesis, characterization, and apphcation of inorganic membranes. 

Liquid membrane type ion-seleetive electrodes (ISEs) provide one of the most versatile sensing methods because it is possible to customize the sensory elements to suit the structure of the analyte. A wealth of different synthetic and natural ionophores has been developed, in the past 30 years, for use in liquid membrane type ISEs for various inorganic and organic ions [1], In extensive studies [2-4], the response mechanism of these ISEs has been interpreted in terms of thermodynamics and kinetics. However, there have been few achievements in the characterization of the processes occurring at the surface of ISEs at molecular level. 

Feuillade, V.C. and W.G. Haije, Characterization of Hydrotalcite Materials for C02 Selective Membranes, Proceedings of the 9th International Conference on Inorganic Membranes, Lillehammer, 25-29, June 2006. 

There is a clear need for the synthesis and more complete characterization of new PEM polymeric materials. Polymers bearing functional moieties for proton conduction might also be designed to serve as a host for inorganic compounds to afford a proton conducting component in a blend, as well as a standalone PEM. The two current hurdles for polymeric membranes are the high protonic conductivity at low water contents (e.g. under conditions of 120 °C and... 

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