Alkaline poly sulfone

Interesting observations are made, if a polymeric adsorbate is capable of more than one mechanism of adsorption. If poly(styrene sulfonate) (PSS) is adsorbed on carbon black which contains multivalent cations on its surface, the adsorption depends strongly on the nature of the cations and on pH, with a maximum near pH 7. At very alkaline pH s, the OH ions compete with the sulfates for the cations and the PSS adsorption drops to the low values of hydrophobic bonding between the carbon itself and the PSS backbone. The latter low values are also obtained, if PSS is adsorbed on the same carbon after purification, i.e. when oxygen and/or the cations were removed. This adsorption of PSS is now pH independent (29). 

A large number of macromolecules complementary to PMAA, namely polyvinylpyrrolidone, polyvinylpyridine, polyacrylamide, poly(vinyl alcohol), poly(ethylene oxide), oligoethylenimine, poly(sodium styrene sulfonate), polycations of the integral type ionen (2X) were used as P2 and P3. The pH of the media strongly influences the studied reactions of complex formation. For example, in PVPy + PVP + PMAA or OEI + PEO + PMAA systems in the add region, where weak polybases are completely protonized and PMAA does practically not dissodate, complexes with hydrogen bonds (PMAA-PVP or PMAA-PEO) are formed. In neutral medium weak polybases are partially ionizated and polyelectrolyte complexes (PMAA-PVPy, PMAA-OEI) are generated. In the alkaline medium formation of complexes has not been observed. 

The vast catalogue of polymeric materials reviewed here included Nafion composite with inorganic and organic fillers, and non-fluorinated proton conducting membranes such as sulfonated polyimides, poly(arylene ether)s, polysulfones, poly (vinyl alcohol), polystyrenes, and acid-doped polybenzimidazoles. Anion-exchange membranes are also discussed because of the facile electro-oxidation of alcohols in alkaline media and because of the minimizatirHi of alcohol crossover in alkaline direct alcohol fuel cells. 

Wang J, Wang J, Li S, Zhang S. Poly(arylene ether sulfone)s ionomers with pendant quaternary ammonium groups for alkaline anion exchange membranes preparation and stability issues. J Membr Sci 2011 368(l-2) 246-53. 

Wang J, Li S, Zhang S. Novel hydroxideconducting polyelectrolyte composed of an poly(arylene ether sulfone) containing pendant quaternary guanidinium groups for alkaline fuel cell applications. Macromolecules 2010 43(8) 3890-6. 

Seo DW, Hossain MA, Lee DH, Lim YD, Lee SH, Lee HC, et al. Anion conductive poly(arylene ether sulfone)s containing tetra-quatemary anunonium hydroxide on flu-orenyl group for alkaline fuel cell application. Electrochim Acta 2012 86 360-5. 

Unlike ring sulfonated polyaniline, the fully sulfonated, water-soluble, polyaniline, poly(2-methoxyaniline-5-sulfonic acid), is shown to be remarkably inert to alkaline dedoping and remains in the conducting emeraldine salt form even in 2.0 M NaOFi [164], The UV-Vis near-infrared spectra of poly(2-methoxyaniline-5-sulfonic acid) solution as a function of plT are shown in Figure 2.28. In water, the absence of a localized polaron band in the range of 750-900 run and presence of a broad absorption in NIR suggests an extended coil conformation... 

The applications of hydrogel in the retention of metal ions were intensively studied [126]. pH-sensitive hydrogels based on poly(N-vinyl-2-pyrrolidon) (PVP), acrylic acid (AAc) and styrene (Sty) were prepared by gamma irradiation [127]. PVP/(AAc-co-Sty) hydrogels were subjected to radiation modification to use them as adsorbent materials for removal of heavy metal ions from aqueous solution. Effect of functionalization of hydrogels by sulfonation (Sf), partial hydrolysis with alkaline solution (NaOH) and treated with the two processes (NaOH/Sf) on metal ion uptake was evaluated, and it results in appreciable uptake of Co ", Cu " and Fe " ions from aqueous solution. 

Studies of the cytocompatibility indicated that all poly (urethane)s are nontoxic. The sulfonic acid groups affect solubility in water imder alkaline conditions and the materials become insoluble in acidic conditions. This pH sensitivity makes the pol5uner attractive for biopiinting applications. By adding acetic acid into an inkjet cartridge and printing it onto a poly(urethane)s solution with a pH above 8.7, precision fabricated scaffolds can be obtained (71). 

PSSA may also be prepared by sulfonation of polyst5rrene or by hydrolysis of poly(re-propyl p-vinylbenzenesulfonate). The latter cases allow preparation of tactic structures. Copol5uners can also be prepared by free-radical copolymerization of appropriate monomers or post-reaction. Poljuners are purified by precipitation of aqueous solutions with methanol, alkaline methanol, or other alcohols. Controlled structure PSSA homopolymers and block copolymers may also be prepared directly in aqueous media via RAFT using 4-cyanopentanoic acid dithiobenzoate as the CTA and V-501 as the radical source (48). NMP has been successfully... 

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