Fluoropolymer membranes functionalization

Perpall, M. W., Smith, D. W., Jr., DesMarteau, D. D. and Greager, S. E. 2006. Alternative trifluorovinyl ether derived fluoropolymer membranes and functionalized carbon composite electrodes for fuel cells. Journal of Macromolecular Science Part C Polymer Reviews 46 297-313. 

Thus, the ability to manipulate and control the surface properties of fluoropolymer membranes is of crucial importance to extend and enhance their functionalities. 

Surface modification and functionalization of fluoropolymer membranes can be achieved via two main approaches, viz., (a) the grafting from and (b) the grafting to approaches (Scheme 8.5). The grafting from method incorporates active sites... 

One of the first fictional fluoropolymers was poly-1,2,2-trifluorostyrene. On one hand, it has much better oxidation and chemical resistance in comparison with common hydrocarbon polymers and, on the other hand, a wide range of functional groups can be attached to the aromatic ring. A sulfonated polymer was successfully used as a membrane for fuel cells by General Electric Co.3... 

As was noted above, functional fluoropolymers produced by copolymerization of fluoroolefins with functional PFAVE have several unique properties, with the main disadvantage of these materials being the extremely high cost of functional monomers and the resulting high cost of the functional polymers produced from them. The fact that they are so expensive limits their wider industrial application in other fields such as catalysis and membrane separation, except for chlorine-alkali electrolysis and fuel cells, where the only suitable materials are fully fluorinated polymers because of the extreme conditions associated with those processes. 

Grafting of functional monomers onto fluoropolymers produced a wide variety of permselective membranes. Grafting of styrene (with the following sulfonation), (meth)acrylic acids, 4-vinylpyridine, A-vinylpyrrolidone onto PTFE films gave membranes for reverse omosis,32-34 ion-exchange membrane,35-39 membranes for separating water from organic solvents by pervaporation,49-42 as well as other kinds of valuable membranes. 

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