Sulfonic acid, adsorption

Anilinonaphthalene-l-sulfonic acid ammonium salt, which scarcely fluoresces in aqueous solution, is stimulated to intense fluorescence by long-wavelength UV light (A = 365 run) if it is dissolved in nonpolar solvents or adsorptively bound to nonpolar molecular regions [3]. 

In tests conducted by Smart and Laidlaw, adsorption was the least prevalent in compounds containing sulfonic acid groups. This seemed to be due to their low pK, which gives an anionic group that repels the usual anionic charges of the adsorbents. 

As conclusion, bifunctional fibers having both phosphonic acid and sulfonic acid groups exhibit the characteristic metal ion selectivity and high breakthrough capacities in addition to the extremely fast adsorption rates. Studies on behavior of FPS-f in adsorption of other heavy metals like Fe(III) are now in progress. The bifunctional fiber developed in this work is attractive to application to the protection of the environment because of its extremely rapid adsorption rates and characteristic metal ion selectivity. 

The surface character of fibres influences their affinity towards various chemical additives by, for example, their adsorption properties and also in their tendency to flocculate. Cellulosic fibres, because of the presence of acidic groups which are introduced during chemical pulping and bleaching, are mildly anionic. These acidic groups may be carboxylic (COOH) or in some cases sulfonic acid (S03H) and they are able to dissociate to leave a net negative... 

Solute adsorption can be minimized most effectively by capillary wall coating, thereby decreasing the free energy of hydrophobic or ionic interactions. Coating can be achieved either by covalently bonded organic modifiers, e.g., polyacrylamides, sulfonic acids, polyethylene glycols, maltose, and polyvinyl pyrolidinone, or by dynamic deactivation (i.e., addition of... 

The electrode kinetics of cathodic oxygen reduction at Pt in contact with the acidic polymer is enhanced by a factor of at least 10 compared to aqueous sulfuric or phosphoric acid at temperatures of 50 to 80°C (759) because the sulfonic acid groups interact adsorptively less with Pt than S04 2 or P04 ions, leaving the greater part of the Pt surface free for adsorption of O2. 

Ethers. The polycondensation of diphenyl ether and furfural (1 1.5mole ratio) in presence of sulfuric acid yields a resin which has been sulfonated by sulfuric acid at 50 °C for 10 h to give a cation-exchange resin The swelling and the exchange capacity of the product increase with the amount of sulfuric acid present during the polycondensation and are higher for a resin obtained by polycondensation in carbon tetrachloride than the one prepared in absence of solvent. The thermal stability of sulfonated diphenyl ether-furfural resin is more than that of KU-1 and comparable to that of KU-2. The sulfonic acid resin derived from the copolymer obtained by the polymerization of diphenyl ether and furfural at a mole ratio of 1 2 in carbon tetrachloride has optimum adsorption and catalytic activity... 

Porous affinity membranes based on hydrolyzed poly(GMA-co-EDMA) grafted with glicidyl methacrylates oligomers were also reported [2,60]. Tennikova et al. [2] prepared functionalized macroporous poly(GMA-co-EDMA) membranes by reaction with propane sulfone, diethylamine, or water, leading to the formation of corresponding sulfonic acid, diethylamino or diol-derivatized stationary chromatographic phases. Unfortunately, the poly(GMA-co-EDMA) membranes are mechanically weak and due to their hydrophobic character may cause nonspecific adsorption of proteins. 

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