In the title compound, 4-[3-(3-sulfonato-pyridin-1-ium-4-yl)prop-yl]pyridin-1-ium-3-sulfonate, C(13)H(14)N(2)O(6)S(2), the mol-ecule is zwitterionic, with the sulfonic acid proton transfered to the basic pyridine N atom. Also, the structure adopts a butterfly-like conformation with the sulfonate groups on opposite sides of the 'wings'. The dihedral angle between the two pyridinium rings is 83.5...

sulfonated poly (ether ether ketone) (speek) with a low degree of sulfonation (ds = 40%) was prepared for proton exchange membrane fuel cells (pemfc). poly (ether ether ketone) (peek) was sulfonated in concentrated h2so4 under n2 atmosphere and characterized by the hydrogen nuclear magnetic resonance (h-nmr) technique. after preparation of the speek polymer, the obtained polymer was dissolved i...

For improving the hydrolytic stability of sulfonated polyimides consisting five membered anhydrides, novel (NSPIs) were prepared via polymerization 3,3?,4,4?-benzophenonetetracarboxylic dianhydride (BTDA), with a diamine monomer pendant sulfonic acid group and 4,4-oxydianiline. Water uptake this NSPI an excellent film-forming ability was almost equal to that Nafion® 117, while their ion exchang...

Polyethersulfone (PES) films are widely employed in the construction of membranes where there is a desire to make surface more hydrophilic. Therefore, UV photo-oxidation was studied order oxidize PES and increase hydrophilicity. using low pressure mercury lamps emitting both 253.7 184.9 nm radiation were compared with only photons. The modified surfaces characterized X-ray photoelectron spectro...

Aromatic nitration has been used to modify the polymer mam chain of polysulfone and polyethersulfone Alteration m the gas separation charactenstlcs of homogeneous membranes made out of these polymers could be observed upon nitration Generally, separation factors for gas mixtures of CO&H, increased while the permeability decreased Remarkably, a decreasing dlffuslvlty for both gases upon nitratio...

To generate polyethersulfone membranes with a biocatalytically active surface, pancreatin was covalently immobilized. Pancreatin is a mixture of digestive enzymes such as protease, lipase, and amylase. The resulting membranes exhibit self-cleaning properties after “switching on” the respective enzyme by adjusting pH and temperature. Thus, the membrane surface can actively degrade a fouling laye...