Modified poly membrane

G. Asman, O. Sanli. Ultrafiltration of Fe (III) solutions in the presence of poly(vinyl alcohol) using modified poly(methyl methacrylate-co-methacrylic acid) membranes, J. Appl. Polym. Sci. 64 (1997) 1115— 1121. 

Fig. 12 SEM of membrane surfaces, a unmodified BC, b to d poly(acrylic acid)-modified BC membranes formed by time-dependent UV irradiation (b 5 min. c 10 min. d 20 min). Reprinted with permission from [56]...

Traditional polymers for separations in water have a limited chemical resistance and are not useful for solvent separations. Some may be applicable in nonaggressive solvents such as methanol and ethanol due to crosslinking, additives or additional interlayers, but not in any other solvent modified polyamide membranes and poly (ethersulfone) membranes are typical examples. 

Car A, Stropnik C, Yave W et al (2008) PEG modified poly(amide-b-ethylene oxide) membranes for C02 separation. J Membr Sci 307(l) 88-95... 

Jansen, J. C., Macchione, M., and Drioli, E. (2005), High flux asymmetric gas separation membranes of modified poly(ether ether ketone) prepared by the dry phase inversion technique, /. Membr. Sci., 255,167-180. 

Applications to polymer chemistry have also been proposed. Interestingly. the adhesion toward itself. Al or stainless steel, of polythene or TeHon with epoxyresins adhesives is considerably improved by a glow discharge polymerization of methane (or etheiie. ethyne) on the polymer surface, CH4 giving the best results (33). Such a modification of polymer surfaces has also received attention within the scope of modifying poly mer membrane compatibility with blood for medical applications. Various o nic compounds (even CH4 > have been studied in this context, where an ultrathin layer (< 1000 is sufficient to alter blood compatibility 134). 

Polymer films have been obtained by plasma polymerization of hexafluorobenzene, N-vinylpyrrolidine, and chloracrylonitrile (Munro). Higuchi et al. have shown that irradiation of an azobenzene-modified poly(Y-methyl-L-glutamate-CO-L-glutamic acid) in bilayer membrane vesicles of distearyldimethylammonium chloride leads to trans-cis isomerization of the polymer this leads to transfer of the polypeptide from the hydrophobic bilayer membrane interior to the hydrophilic surface. As a result, there was a decrease in the ion permeability through the bilayer membrane and the formation of intervesicular adhesion. Eisner and Ritter have prepared photosensitive membranes from an aromatic polyamide and a cinnamate that incorporates a liquid crystalline component. 

Yu L, Urban G, Moser I, Jobst G, Gmber H (1995) Photolithographically pattemable modified poly(HEMA) hydrogel membrane. Polymer Bull 35(6) 759-765... 

A.R. Roudman and R.P. Kusy, Uv-visible spectroscopic study of the reaction kinetics of methylpiperadine-modified poly(vinyl chloride)s for use as fixed-state proton carrier membranes, Polymer, 1998, 39, 3641-3649. 

Ferritto, M.S. and D.A. Tirrell, Photoregulation of the binding of an azobenzene-modified poly(methacrylic acid) to phosphatidylcholine bilayer membranes. Biomaterials, 1990, 11, 645-651. 

S. Sridhar, B. Smitha, M. Ramakrishna, and T. M. Aminabhavi. Modified poly(phenylene oxide) membranes for tbe separation of carbon dioxide from methane. J. Membr. Set, 280(l-2) 202-209, September 2006. 

G. Pozniak, 1. Gancarz, and W. Tylus. Modified poly(phenylene oxide) membranes in ultrafiltration and micellar-enhanced ultrafiltration of organic compounds. Desalination, 198(l-3) 215-224, October 2006. 

J. Pieracci, J. V. Crivello, and G. Belfort. Increasing membrane permeability of UV-modified poly(ether sulfone) ultrafiltration membranes. J. Membr. ScL, 202(1-2) 1-16, June 2002. 

Fig. 5.5 Photoresponsive behavior of membranes of an azo-modified poly(L-glutamic acid) containing 12-14 mol% azobenzene groups at 60°C. (a) Membrane potential,...

Bakeri, Gh., Ismail, A.R, Rana, D., Matsuura, T. 2012. Development of high performance surface modified poly-etherimide hollow fiber membrane for gas-liquid contacting processes. Chem. Eng. J. 198-199 327-337. 

S. Chowdhury, P. Kumar, P.K. Bhattacharya, A. Kumar, Separation characteristics of modified poly-sulfone ultrafiltration membranes using NO,, Sep. Purif. Technol. 24 (2001) 271—282. 

Li L, Drillet JF, Macova Z, Dittmeyer R, Jtittner K (2006) Poly(3,4-ethylenedioxy thiophene)-modified Nafion membrane for direct methanol fuel cells. Russ J Electrochem 42 1193-1201... 

Chapter 6 deals with the description of different membranes used in direct alcohol fuel cells. Firstly, the properties of Nafion and its inorganic and organic composites are analyzed, focused on the proton cmiductivity and alcohol permeability, which determine the alcohol selectivity of the modified Nafion membranes. Then, a number of alternative non-fluorinated proton conducting membranes, including sulfonated polyimides, poly(arylene ether)s, polysulfones, poly(vinyl alcohol), polystyrenes, and acid-doped polybenzimidazoles, are described in relation to their selectivity in comparison to Nafion. The chapter includes a comprehensive summary of the relative selectivity of these membranes and their performance in direct alcohol fuel cells. Anion exchange membranes for alkaline direct alcohol fuel cells are also reviewed. 

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