Poly membranes sulfonated

Proton conductivity as a function of lEC for ETFE-g-PSSA = polyethylenetetrafluoroethylene-gra/t-polystyrene sulfonic acid, BAM membrane = substituted poly(trifluorostyrene) sulfonic acid, SPEEK = sulfonated poly(ether ether ketone) and Nafion. (From Peckham, T. J. et al. 2007. Journal of Materials Chemistry 17 3255-3268, and Dolye, M. et al. 2001. Journal of Physical Chemistry B 105 9387-9394.)... 

Another concern for polystyrene- and some aromatic-based PEMs is hydrolysis of fhe sulfonic acid group from aromatic rings as well as hydrolytic cleavage of polymer backbone under fuel cell conditions for aromafic polymers including polyimides, poly(arylene ethers), poly(ether ketones), and poly(ether sulfones). It is well known that the sulfonation of aromafic rings is a reversible process especially at low pH and at elevated temperature (Scheme 3.3). The reversibility of sulfonation, for example, is used in fhe preparafion of trinitrotoluene or picric acid. Por the simplest membrane of the class of arylsulfonic acids (i.e., benzenesulfonic acid), fhe reacfion occurs upon freatment with a stream of superheated steam at 180°C.i ... 

Manea, C. and Mulder, M. 2002. Characterization of polymer blends of poly-ethersulfone/sulfonated polysulfone and polyethersulfone/sulfonated poly-etheretherketone for direct methanol fuel cell applications. Journal of Membrane Science 206 443-453. 

Swier, S., Ramani, V., Fenton, J. M., Kunz, H. R., Shaw, M. T. and Weiss, R. A. 2005. Polymer blends based on sulfonated poly(ether ketone ketone) and poly(ether sulfone) as proton exchange membranes for fuel cells. Journal of Membrane Science 256 122-133. 

Kwan et al. [27] l-Lactate Yoghurt milk, soda, sport drinks, and healthy supplement Salicylate hydroxylase (SHL), L-lactate dehydrogenase (LDH), and pyruvate oxidase (PyOD)/entrapped by a poly(carbamoyl) sulfonate (PCS) hydrogel on a Teflon membrane Clark-type oxygen electrode ... 

An important parameter in a number of fields is the study of inorganic phosphate. Recently, Kwan et al. [206,207] have reported on a screen-printed phosphate biosensor based on immobilised pyruvate oxidase (PyOD) for monitoring phosphate concentrations in a sequencing batch reactor system [206] and in human saliva [207]. The enzyme was immobilised by drop-coating a Nation solution onto the working electrode surface this was then covered by a poly(carbamoyl) sulfonate (PCS) hydrogel membrane. 

Most of today s ultrafiltration membranes are made by variations of the Loeb-Sourirajan process. A limited number of materials are used, primarily polyacrylonitrile, poly(vinyl chloride)-polyacrylonitrile copolymers, polysulfone, poly(ether sulfone), poly(vinylidene fluoride), some aromatic polyamides, and cellulose acetate. In general, the more hydrophilic membranes are more fouling-resistant than the completely hydrophobic materials. For this reason water-soluble... 

Water-insoluble PEC were prepared by mixing oppositely charged polyelectrolytes, e.g. DEAE dextran with CMD [340,341], sodium dextran sulfate, poly(styrene sulfonate) (NaSS) [342], poly(sodium L-glutamate) (PSLG), poly(vinyl alcohol)sulfate [343], or potassium metaphosphate (MPK) [240]. They are useful as membranes or in biomedical applications [343,344]. 

Wang, Y.Q. et al. (2005) Remarkable reduction of irreversible fouling and improvement of the permeation properties of poly(ether sulfone) ultrafiltration membranes by blending with pluronic F127. Langmuir, 21, 11856-11862. 

Polyarylenes, in particular different types of poly(arylene ether ketone)s, have been the focus of much hydrocarbon membrane research in recent years. - - With good chemical and mechanical stability under PEM fuel cell operating conditions, the wholly aromatic polymers are considered to be the most promising candidates for high-performance PEM fuel cell applications. Many different types of these polymers are readily available and with good process capability. Some of these membranes are commercially available, such as poly(arylene sulfone)s and poly(arylene... 

Ballard Advanced Materials (BAM) ionomers are sulfonated copolymers of trifluorostyrene and substimted trifluorostyrene monomers. BAM, a subsidiary of Ballard Power Systems, investigated the conducting polymers based on polyphenylquinoxaline (PPQ). These can be sulfonated in a wide range and were referred to as BAMIG (Ballard first generation) membranes, but these membranes were found to have short durability. To overcome this problem, BAM developed a second generation of advanced membranes based on two distinct material types. The first material type consisted of a series of sulfonated poly(2,6-diphenyl 1,4-phenylene oxide). The second material type consisted of a series of sulfonated poly(arylether sulfone). But the durability of these membranes was also insufficient. Since the durability of previous membranes was limited, Ballard produced a novel family of sulfonated membranes based on a,p,p-ttifluorostyrene monomers and a series of substituted ttifluoro-comonomers... 

Within the realm of BAM2G membranes, a series of partially fluorinated bisphenol A-type poly(arylether) sulfones were synthesized. As mentioned above, these materials initially exhibited acceptable, useful service-life performance, but were unable to provide more than 500 h of continuous running time. This led to the decision that a perfluorinated backbone would be most beneficial in achieving fuel cell longevity in performance and efficiency. Therefore, the a, 3,p-trifluorostyrene monomer was chosen as the most suitable platform on which to build BAM3G polymers [98]. The BAM3G has demonstrated over 100,000 h of cumulative performance in a wide variety of Ballard fuel cell hardware. The BAM3G membranes have... 

The membrane is made of organic, poly(ether sulfone), with a separation limit of approximately 100 kDa, and a transversal flow rate of 1-6 m/s. The entrance pressure to the module is from 6 to 7.5 bar and that of exit is 0.5-1 bar. 

Kaeselev, B., Pieracci, J., and Belfort, G., Photoinduced grafting of ultrafiltration membranes Comparison of poly(ether sulfone) and poly(sulfone), J. Membr. Sci., 194, 245, 2001. 

Polyamide, poly(ether sulfone) helical membrane... 

Typical UF membrane materials are polysulfone (PS), poly ether sulfone (PES), polyetheretherketone (PEEK), cellulose acetate (CA), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polyimide (PI), and polyetherimide (PEI) ... 

Extrude liposomes through a 220-nm polycarbonate fdter 12 times through a poly(ether sulfone) (PES) membrane. 

Mecham, J.B. (2001) Direct polymerization of snlfonated poly (arylene ether) random copolymers and poly(imide) sulfonated poly(arylene ether) segmented copolymers new candidates for proton exchange membrane fuel cell material systems. Ph.D. Thesis, Virginia Polytechnic Institute and State University. 

Insoluble polyelectrolyte complex may be formed when dissolved acidic and basic polyelectrolyte polymers are brought into intimate contact (131). Complex formation is generally agreed to be driven by the increase in entropy associated with the loss of small counterions into the bulk of the solution (132). Polyelectrolyte complex from concentrated solutions of strongly acidic and basic homopolymers has been shown to form sufficiently rapidly to produce a 20-30 nm thick membrane at the solution interface, as was found through reaction of dissolved poly(vinylbenzyl trimethylammonium chloride) with sodium poly (styrene sulfonate) (132). 

For polysalt amphoteric membranes, a cationic polyelectrolyte solution such as poly(benzyl trimethylammonium salt) and an anionic polyelectrolyte solution such as poly(styrene sulfonate) are mixed and a polymer salt precipitated. The polymer salt is then dissolved in a suitable solvent and is formed into a membrane by a casting method.103... 

Figure 5.26 Relationship of Pa50 to the concentration of 1 1 mixed salt solutions of sodium sulfate and sodium chloride using anion exchange membranes with and without anionic polyelectrolyte layers. (O) without the layer ( ) immersed in 1000ppm poly(styrene sulfonic acid) (reduced viscosity of 1.0% solution, r sp/C 0.714 dlg ) solution (X) with 1000ppm polycondensation product of sodium naphthalene sulfonate and formaldehyde (MW ca. 1000) solution. After an anion exchange membrane (NEOSEPTA AM-1 strongly basic anion exchange) had been immersed in the anionic polyelectrolyte solution for 17 h at 25.0 °C, 1 1 mixed salt solutions of sodium sulfate and sodium chloride were electrodialyzed for 60 min at 25.0 °C under vigorous agitation.

Surface modification in order to improve the hydrophilicity of membrane surface can be achieved by blending surface modifying macromolecules to the base material. Blends of phenolphthalein poly(ether sulfone) and poly(acrylonitrile-co-acrylamido methylpropane sulfonic acid), a material that contains charged groups, have been prepared. It was found... 

Hollow fiber membranes made from poly(imide)/sulfonated PES, with a phthalide group, exhibit a high selectivity in the vapor permeation of mixtures of methanol and methyl-terf-butyl ether (MTBE) as high as 12,000. The structures of the polymers used are shown in Figure 7.11. 

M.-L. Luo, J.-Q. Zhao, W. Tang, and C.-S. Pu. Hydrophilic modification of poly(ether sulfone) ultrafiltralion membrane surface by self-assembly of Ti02 nanoparticles. AppZ. Surf. ScL, 249(l-4) 76-84, August 2005. 

---