Membrane science development

By 1960, the elements of modem membrane science had been developed, but membranes were used in only a few laboratory and smaU, specialized industrial appHcations. No significant membrane industry existed, and total annual sales of membranes for aU appHcations probably did not exceed 10 million in 1990 doUars. Membranes suffered from four problems that prohibited their widespread use as a separation process they were too unreHable, too slow, too unselective, and too expensive. Partial solutions to each of these problems have been developed since the 1960s, and in the 1990s membrane-based separation processes are commonplace. 

In the recent years, many researchers have devoted attention to the development of membrane science and technology. Different important types of membranes, such as these for nanofiltration, ultrafiltration, microfiltration, separation of gases and inorganic membranes, facilitated or liquid membranes, catalytic and conducting membranes, and their applications and processes, such as wastewater purification and bio-processing have been developed [303], In fact, almost 40 % of the sales from membrane production market are for purifying wastewaters. 

Kreuer, K. D. 2001. On the development of proton conducting membranes for hydrogen and methanol fuel cells. Journal of Membrane Science 185 29-39. 

Kerres, J., Cui, W., Disson, R. and Neubrand, W. 1998. Development and characterization of cross-linked ionomer membranes based upon sulfinated and sulfonated PSU-cross-linked PSU blend membranes by disproportionation of sulfinic acid groups. Journal of Membrane Science 139 211-225. 

We have tried to relate the performance of a deteriorated membrane to its structure by classical methods. Recent advancement in the techniques of morphological and physicochemical analyses is remarkable, and is much contributing to better understanding of the membrane behaviour. We have now various types of RO membranes made of synthetic polymers available, and most these analytical procedures are applicable for the analysis of these membranes. Investigations on the membrane structures are much more required, and they will reveal the relations between materials and structure, and structure and performance. We believe these Investigations will contribute to development not only in the membrane Itself, but in the application of the membrane. We hope the progress of membrane science will expand RO marke t. 

Keenan, T. W., Dylewski, D. P., Woodford, T. A. and Ford, R. H. 1983A. Origin of milk fat globules and the nature of the milk fat globule membrane. In Developments in Dairy Chemistry, Vol. 2 Lipids, P.F. Fox (Editor). Applied Science Publishers, London, pp. 83-118. 

This book provides a general introduction to membrane science and technology. Chapters 2 to 4 cover membrane science, that is, topics that are basic to all membrane processes, such as transport mechanisms, membrane preparation, and boundary layer effects. The next six chapters cover the industrial membrane separation processes, which represent the heart of current membrane technology. Carrier facilitated transport is covered next, followed by a chapter reviewing the medical applications of membranes. The book closes with a chapter that describes various minor or yet-to-be-developed membrane processes, including membrane reactors, membrane contactors and piezodialysis. 

Livingston, A.G., Arcangeli, J.P., Boam, T., Zhang, S., Marangon, M. and Freitas, L.M. (1998) Extractive membrane bioreactors for detoxification of chemical industry wastes process development Journal of Membrane Science, 151, 29. 

As the pore diameter increases in size (s decreases) relative to molecular or colloidal dimensions, less restrictions are imposed on the motions of contained species. Thus the exclusion effect gradually subsides as the pore size increases and consequently K-+1. For the separation of two molecules of different size, it is important to pick a pore diameter that will substantially exclude one species but not another. Pore size selection is thus of utmost importance in membrane science and in choosing a support for size exclusion chromatography (SEC). Aspects of pore size optimization in SEC based on the above partitioning theory have been developed [28]. 

Smith B, Sridhar S, Khan A, (2005). Solid polymer electrolyte membranes for fuel cell applications-a review. Journal of Membrane Science 259 10-26 Sopian K, Wan Daud W, (2006). Challenges and future developments in proton exchange membrane fuel cells. Renewable Energy 31 719-727 Srinivasan S, (2006). Fuel cells From fundamentals to applications. Springer Science and Business Media LLC, New York... 

Yoshino, Y., Suzuki, T., Nair, B.N., Taguchi, H., and Itoh, N., Development of tubular substrates, silica based membranes and membrane modules for hydrogen separation at high temperature, Journal of Membrane Science, 267, 8-17, 2005. 

In the popular fluid mosaic model for biomembranes, membrane proteins and other membrane-embedded molecules are in a two-dimensional fluid formed by the phospholipids. Such a fluid state allows free motion of constituents within the membrane bilayer and is extremely important for membrane function. The term "membrane fluidity" is a general concept, which refers to the ease of motion for molecules in the highly anisotropic membrane environment. We give a brief description of physical parameters associated with membrane fluidity, such as rotational and translational diffusion rates, order parameters etc., and review physical methods used for their determination. We also show limitations of the fluid mosaic model and discuss recent developments in membrane science that pertain to fluidity, such as evidence for compartmentalization of the biomembrane by the cell cytoskeleton. 

Multifunctional and adaptive membranes, and miniaturized and integrated separative devices are current trends in membrane science research and development. Increasing societal requests in terms of environmental protection, health, energy savings, etc., are long-term driving forces for such activities. 

A continuous research work on membrane properties and fundamental aspects of transport phenomena in the various membrane operations is important for the fumre of membrane science and technology. There is a need for both basic and applied research to develop new membranes with improved properties and new membrane processes. These research efforts must take into account the studies done in other areas such as supramolecular chemistry, molecular imprints materials, nanotechnology, nonlinear optics, studies on biological membranes and biological phenomena, etc. 

X). M. Bartlett, M. R. Bird, and J. A. Howell, An experimental study for the development of a qualitative membrane cleaning model. Journal of Membrane Science 105,147-157 (1995). 

Matsuyama, H., Teramoto, M., and Iwai, K. Development of a new functional cation-exchange membrane and its application to facilitated transport of C02. Journal of Membrane Science, 1994, 93, 237. 

Ismail, A.F. David, L.I.B. A review on the latest development of carbon membranes for gas separation. Journal of Membrane Science 2001,... 

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