Cation sulfonated

Another study involving cation—sulfonate interactions in Nafion (1200 EW) is that of Yeager, who investigated the property of equilibrium ion exchange selectivity at 25 The results of this study are... 

Cation—sulfonate interactions, as well as proton mobility, are also expressed in the electrical conductance behavior of these membranes. Many studies of this property have been reported, and there is no attempt in this review to cite and describe them all. Rather, a few notable examples are chosen. Most testing is done using alternating current of low voltage to avoid complications in the form of chemical... 

Let us examine a silica-based cationic (sulfonate) ion exchange separation (Fig. 4.9). The column is equilibrated in 50mM sodium acetate. An injection of amines and an alcohol in the mobile phase is made. The same mobile phase, or one containing increased amounts of sodium acetate, is used to elute fractions. 

Equations 4.1-4.6 illustrate the fundamental conceptual steps involved in describing the dissociation characteristics of strong cation (sulfonic acid) and strong anion (quaternary ammonium hydroxide) exchangers, where the bar notation represents the resin phase. Once understood, dissociation in the resin phase is implied where appropriate, as illustrated by equations 4.7 and 4.8. 

Figure 1.7. An ion-exchange HPLC chromatogram of essential amino acids using a cationic sulfonate column and detection with post-column reaction. Note that Na315 and Na740 are prepackaged eluents containing sodium ion and buffered at pH of 3.15 and 7.40, respectively. Trione is a derivatization reagent similar to ninhydrin. Chromatogram courtesy of Pickering Laboratories.

Ion exchange Cations sulfonic carboxylic acid Anions functionalized amines Aqueous buffer, (may contain organic solvent) Metal ions, halides, oxyanions, transistion metals... 

It was of interest to compare the spectra of PSSA ionomers as a function of sulfonate composition in light of the observation of a duster mode present in their FIR spectra. As shown in Table 5, the value of Vg hills somewhat as the content of sulfonate increases. This is consistent with increasing numbers of cations in large ionic clusters at higher sulfonate concentrations, because the vibrations of the cations in such domains are expected to have both a larger effective mass and lower effective force constant since increased screening lowers the cation-sulfonate site attraction. 

PPO and PPOBr were sulfonated by reacting with chlorosulfonic acid in chloroform [49]. The degree of sulfonation was determined by acid-base titration method. Under the reaction conditions only mono-aryl substitution of PPO and PPOBr occurred. The polymers were converted to the salt form by replacing the proton of the sulfonic acid group with Na-cation. Sulfonated PPO (SPPO) and sulfonated brominated PPO (SPPOBr), both in the Na-cation form (SPPONa and NaSPPOBr), were used for water removal studies. 

Complexation of bromine with iron(III) bromide makes bromine more elec trophilic and it attacks benzene to give a cyclohexadienyl intermediate as shown m step 1 of the mechanism (Figure 12 6) In step 2 as m nitration and sulfonation loss of a proton from the cyclohexadienyl cation is rapid and gives the product of electrophilic aromatic substitution... 

Sulfonate exchangers contain the group —SO3, which is strongly acidic and completely dissociated whether in the H form or the cation form. These exchangers are used for cation exchange. 

Cation exchange resins — gel type—strongly acidic—sulfonic acid functionality ... 

Cation exchange resin— -macroreticular type- — sulfonic acid functionality... 

Direct, acid catalyzed esterification of acryhc acid is the main route for the manufacture of higher alkyl esters. The most important higher alkyl acrylate is 2-ethyIhexyi acrylate prepared from the available 0x0 alcohol 2-ethyl-1-hexanol (see Alcohols, higher aliphatic). The most common catalysts are sulfuric or toluenesulfonic acid and sulfonic acid functional cation-exchange resins. Solvents are used as entraining agents for the removal of water of reaction. The product is washed with base to remove unreacted acryhc acid and catalyst and then purified by distillation. The esters are obtained in 80—90% yield and in exceUent purity. 

Flotation reagents are used in the froth flotation process to (/) enhance hydrophobicity, (2) control selectivity, (J) enhance recovery and grade, and (4) affect the velocity (kinetics) of the separation process. These chemicals are classified based on utili2ation collector, frother, auxiUary reagent, or based on reagent chemistry polar, nonpolar, and anionic, cationic, nonionic, and amphoteric. The active groups of the reagent molecules are typically carboxylates, xanthates, sulfates or sulfonates, and ammonium salts. 

The basic flow sheet for the flotation-concentration of nonsulfide minerals is essentially the same as that for treating sulfides but the family of reagents used is different. The reagents utilized for nonsulfide mineral concentrations by flotation are usually fatty acids or their salts (RCOOH, RCOOM), sulfonates (RSO M), sulfates (RSO M), where M is usually Na or K, and R represents a linear, branched, or cycHc hydrocarbon chain and amines [R2N(R)3]A where R and R are hydrocarbon chains and A is an anion such as Cl or Br . Collectors for most nonsulfides can be selected on the basis of their isoelectric points. Thus at pH > pH p cationic surfactants are suitable collectors whereas at lower pH values anion-type collectors are selected as illustrated in Figure 10 (28). Figure 13 shows an iron ore flotation flow sheet as a representative of high volume oxide flotation practice. 

Soluble Salt Flotation. KCl separation from NaCl and media containing other soluble salts such as MgCl (eg, The Dead Sea works in Israel and Jordan) or insoluble materials such as clays is accompHshed by the flotation of crystals using amines as coUectors. The mechanism of adsorption of amines on soluble salts such as KCl has been shown to be due to the matching of coUector ion size and lattice vacancies (in KCl flotation) as well as surface charges carried by the soflds floated (22). Although cation-type coUectors (eg, amines) are commonly used, the utUity of sulfonates and carboxylates has also been demonstrated in laboratory experiments. 

Although catalytic hydration of ethylene oxide to maximize ethylene glycol production has been studied by a number of companies with numerous materials patented as catalysts, there has been no reported industrial manufacture of ethylene glycol via catalytic ethylene oxide hydrolysis. Studied catalysts include sulfonic acids, carboxyUc acids and salts, cation-exchange resins, acidic zeoHtes, haUdes, anion-exchange resins, metals, metal oxides, and metal salts (21—26). Carbon dioxide as a cocatalyst with many of the same materials has also received extensive study. 

Amphoteric Detergents. These surfactants, also known as ampholytics, have both cationic and anionic charged groups ki thek composition. The cationic groups are usually amino or quaternary forms while the anionic sites consist of carboxylates, sulfates, or sulfonates. Amphoterics have compatibihty with anionics, nonionics, and cationics. The pH of the surfactant solution determines the charge exhibited by the amphoteric under alkaline conditions it behaves anionically while ki an acidic condition it has a cationic behavior. Most amphoterics are derivatives of imidazoline or betaine. Sodium lauroamphoacetate [68647-44-9] has been recommended for use ki non-eye stinging shampoos (12). Combkiations of amphoterics with cationics have provided the basis for conditioning shampoos (13). 

Strong" Acid Cation Excha.ngers. AH strong acid-type resins are made from styrene—DVB copolymers, with the exception of a minor quantity of phenoHc resin. Batch sulfonation using commercial strength sulfuric acid [8014-95-1] is common. 

Three generations of latices as characterized by the type of surfactant used in manufacture have been defined (53). The first generation includes latices made with conventional (/) anionic surfactants like fatty acid soaps, alkyl carboxylates, alkyl sulfates, and alkyl sulfonates (54) (2) nonionic surfactants like poly(ethylene oxide) or poly(vinyl alcohol) used to improve freeze—thaw and shear stabiUty and (J) cationic surfactants like amines, nitriles, and other nitrogen bases, rarely used because of incompatibiUty problems. Portiand cement latex modifiers are one example where cationic surfactants are used. Anionic surfactants yield smaller particles than nonionic surfactants (55). Often a combination of anionic surfactants or anionic and nonionic surfactants are used to provide improved stabiUty. The stabilizing abiUty of anionic fatty acid soaps diminishes at lower pH as the soaps revert to their acids. First-generation latices also suffer from the presence of soap on the polymer particles at the end of the polymerization. Steam and vacuum stripping methods are often used to remove the soap and unreacted monomer from the final product (56). 

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