Sulfonated Cation Exchange Research Articles

Using macroporous N-chlorosulfonamide S/DVB copolymer as an aid to iron removal from water

Abstract The de-ironing of water is a basic stage in water-treating technology. Consequently, the oxidation of easily soluble Fe(II) to poorly soluble Fe(III) compounds is indispensible. In order to oxidize Fe(II) ions to Fe(III), a macromolecular and macroporous product in bead form was used: polystyrene cross-linked by divinylbenzene, which contains pendant N-chlorosulfonamide groups in both the sodium and hydrogen forms. To assist the process of removing residual iron from water, this polymer - a macromolecular analog of Chloramine T, containing more than 4.0 mequiv of active chlorine/g - was prepared, starting from the sulfonate cation exchanger Amberlyst 15 by a three-step transformation of its functional groups. The investigations were carried out using both the batchwise and column methods, and 0.0025 M as well as 0.02 M FeSO4 solutions with different acidity were used. We found that the oxidation of ferrous ions to ferric by N-chlorosulfonamide copolymer was effective and was favored by a low pH. The oxidative ability of the copolymer was 225 mg Fe(II)/g. We established that the oxidation reaction could be operated in two directions. In acidic media (pH < 2.5), Fe(III) ions remained in the solution as products of the reaction. The higher the pH, the more the poorly soluble ferric compounds sedimented in the inner structure of the copolymer beads. In this way, new hybrid materials were obtained, i.e., by ferrous/ferric oxides and hydroxides, by nanoparticles, modified materials which can serve as specific reacting sorbents and catalysts.

Quantum chemical calculation of hydration for alkali metal salts

Calculations using the GAUSSIAN 03 program package were performed to determine the hydrated structures of lithium, potassium, LiCl, NaCl, and sulfonic cation exchanger in the form of alkali metal ions. For ions with positive hydration, the distance between the radii of the first and second spheres of hydration water is larger than in pure water; for ions with negative hydration, this distance is smaller. Salts with different types of hydration for cation and anion have hydrated structures similar to those of ions with negative hydration.

Sulfonic cation exchangers based on immobilized cis-Calix[4]resorcinolarenes

New sulfonic cation exchangers based on immobilized calix[4]resorcinolarenes were prepared. Their ion-exchange properties toward Na+, Cu2+, [Pd(NH3)4]2+, In3+, and Sn4+ ions were studied in a wide pH range, and their chemical stability was examined.

Preparation and study of properties of sulfonic acid ion exchangers based on polypropylene fibrous material

The possibility of raising the static exchange capacity of strongly acidic ion-exchange materials produced by grafting of styrene onto polypropylene fibers, with the subsequent sulfonation of the products synthesized, was analyzed. The chemical and osmotic stabilities of the sulfonic cation exchangers obtained and their frost resistance in freeze-thaw cycles were studied.

Synthesis, Structure, and Thermal Stability of a Sulfonic Cation Exchanger Grafted to Carbonized Fiber

A new kind of sulfonic cation exchanger based on carbonized fiber modified with poly(styrene-divinylbenzene) was prepared by radiation grafting. The structural features and thermal stability of the cation exchangers prepared were studied.

Methyl tert-Amyl Ether Synthesis Catalyzed by a Sulfonic Cation Exchanger: The Effect of the Degree of Hydration of the Cation Exchanger on the Catalytic Activity and Reaction Mechanism

The catalytic properties of the fibrous sulfonic acid cation exchanger FIBAN K-1 in methyl tert-amyl ether synthesis are studied as a function of its water content. Reducing the degree of hydration of the cation exchanger to <2 H2O molecules per SO3H group diminishes the proportion of the desired product in the catalysate. According to 13C NMR data, protonation of methylbutenes in the air-dry cation exchanger phase (which contains 4 H2O molecules per SO3H group) involves [nH2O] ⋅ H+ species and is accompanied by olefin hydration and the formation of protonated tert-amyl alcohol.

Sorption, acid, and catalytic properties of a sulfonic cation exchanger supported on the carbon fiber

Distribution in strength of the acid centers in sulfonic cation in the form of exchanger granules and fibers was studied by the novel modification of the thermal desorption method.

Thermal stability and activity in hydrogen oxidation of palladium catalysts supported on fibrous sulfonic cation exchanger in the hydrogen and magnesium forms

The effect of reduced palladium on the thermal stability of the hydrogen and magnesium forms of FIBAN K-1 fibrous sulfonic cation exchanger was studied. The activity of palladium catalyst supported by the H and Mg forms of the cation exchanger in hydrogen oxidation was determined, as influenced by the temperature of treatment of the catalyst with the reaction mixture.

Effect of Palladium on Thermal Degradation of Fiban K-1 Fibrous Sulfonic Cation Exchanger. Study by Thermal Analysis, Epr Spectroscopy, and Mass Spectrometry

Thermal degradation of palladium-containing samples of Fiban K-1 fibrous sulfonic cation exchanger in the H form fabricated by ion exchange and reduced with hydrazine hydrate was investigated by methods of DTA, x-ray phase analysis, mass spectrometry, and EPR spectroscopy. It was found that palladium in the reduced state added to the cation exchanger in relatively small amounts, 1.5-2.5 wt. %, stabilizes the hydrocarbon matrix (increases the temperature of the onset of desulfurization of the sulfonic cation exchanger and thermal degradation of the hydrocarbon matrix). With a higher content (14%), palladium significantly changes these characteristics, manifested by a decrease in the temperature of the onset of desulfurization of the ion exchanger and thermal degradation of the hydrocarbon matrix.

Effect of Palladium on Thermal Degradation of Fiban K-1 Fibrous Sulfonic Cation Exchanger. Ir Spectroscopic Study

Vacuum thermal degradation of palladium-containing samples of Fiban K-1 fibrous sulfonic cation exchanger in the H form, fabricated by ion exchange and reduced with hydrazine hydrate, was investigated by IR spectroscopy. It is shown that the presence of reduced palladium in a highly disperse state in the matrix of the ion exchanger causes the most rapid decrease in water bound as the “water—water” type and an increase in the amount of water bound with a sulfo group. It was found that carbonyl-containing complexes are formed in vacuum thermal degradation of palladium-containing samples.

Use of Microspherical Sulfonated Hypercrosslinked Polystyrene in Ion Chromatography

The possibility of applying sulfonated cation exchangers on the basis of hypercrosslinked polystyrene (HCPS) of different ion-exchange capacity for the ion-chromatographic separation of alkali metal and ammonium cations was demonstrated. The effect of the nature and concentration of the eluent, the temperature of the chromatographic column, additions of an organic solvent to the eluent, and the ion-exchange capacity of the sorbent on the retention of cations was examined. An unusual selectivity of the sorbent for lithium and ammonium cations was found; the elution order can change for the Li+/Na+ and Rb+/NH+ 4 pairs depending on the nature of the eluent, the temperature, additions of an organic solvent, and the structural characteristics of the sorbent. When dilute solutions of nitric acid are used as the eluent, the following elution order of cations was obtained: Na+ < Li+ < K+ < NH+ 4 < Rb+ < Cs+ Lt Mg2+ < Sr2+ < Ca2+ < Ba2+. Under the optimum conditions of separation (1 mM solution of sulfuric acid, 20°C) on sulfonated HCPS with an ion-exchange capacity of 0.07 mequiv/g, the separation of ammonium and alkali metal cations was achieved within 17 min.

The use of nonendcapped C18 columns in the cleanup of clenbuterol and a new adrenergic agonist from bovine liver by gas chromatography-tandem mass spectrometry analysis.

More specific official methodology is needed to survey the illegal use of clenbuterol in animal production plus the synthesis of new compounds that currently elude routine analytical methods. The identification of a new adrenergic agonist, N1-(2-(4-amino-3,5-dichlorophenyl)-2-hydroxyethyl)-N1-isopropyl-propanamide (known as compound A) in animal feed has prompted studies to verify if the existing cleanup procedures developed for clenbuterol are really effective. This study considers the ion-exchange mechanism on cyanopropyl (CN), sulfonic cation exchange (SCX), mixed phase (MPH) (C8 + SCX), and nonendcapped C18 (C18NE) solid-phase extraction (SPE) columns. Results indicate that compound A (by contrast with clenbuterol) is not efficiently retained on the CN, SCX, and MPH SPE columns (recovery <10%). This finding thus leads to the development of a gas chromatography-tandem mass spectrometry procedure based on C18NE SPE that is able to purify both agonists from bovine livers spiked at 0.5, 1.0, and 2.0 ppb with a mean recovery of 93% for clenbuterol and 92% for compound A.

Activity of palladium catalysts based on FIBAN K-1 fibrous sulfonic cation exchanger in reaction of hydrogen oxidation

For palladium catalysts based on FIBAN K-1 fibrous sulfonic cation exchanger (Li+, Na+, Rb+, Cs+,Mg2+,Ca2+, Ba2+ forms) the dispersity and depth distribution of palladium metal in the fiber and the activity of the catalyst in hydrogen oxidation were studied in relation to the conditions of the synthesis and activation.

Dynamics of probe in network of polymeric cation exchanger studied by Fourier transform analysis of Mössbauer spectra

Limited diffusion of the ferric hydroxide (ferrihydrite) nanoparticles in the polymeric network of the AG 50W-X2 sulfonated cation exchanger solvated with aqueous solutions of glycerol (70 and 90 wt.%) was studied in the temperature interval from 90 to 293 K. The Mossbauer spectra were obtained in three windows (250, 25, and 5 mm/s) because of large line broadenings observed in the experiment. The procedure of “seaming” of the time-dependent correlation functions obtained by the Fourier transform analysis of the initial Mossbauer spectra made it possible to observe the behavior of the function in the extremely wide time range from 0.4 to 360 ns. The observed plateau of the function at long times is a direct proof of the limited nature of the motion. The experimental data were interpreted in the framework of physical models of limited diffusion.

Influence of Exchangeable Cation on Dehydration and Thermal Stability of FIBAN K-1 Fibrous Sulfonic Cation Exchanger

The influence of exchangeable cation on dehydration, desulfonation, and thermal oxidative degradation of FIBAN K-1 fibrous sulfonic cation exchanger in the hydrogen, alkali metal, and alkaline-earth metal forms was studied.

Activity of Polymeric and Zeolite-Containing Catalysts in Production of Methyl tert-Butyl Ether

The effect of structural and acid characteristics of catalysts of various nature (sulfonic cation exchangers of the KU-23 type and high-silica zeolite of the ZSM-5 type) on their activity and selectivity in production of methyl tert-butyl ether from isobutylene and methanol was studied.

Effect of Cationic Form of a Fibrous Sulfonic Cation-Exchange Resin on Sorption of Tetramminepalladium(II) and Its Cross-Sectional Distribution

The effect of the nature of exchangeable cation (Na+, Mg2+, Ba2+, La3+) in FIBAN K-1 fibrous sulfonic cation-exchange resin on sorption of tetramminepalladium(II) and its cross-sectional distribution in fabrication of Pd catalysts is studied.

SIMULTANEOUS DETERMINATION OF HEAVY AND TRANSITION METALS IN BIOLOGICAL SAMPLES BY CHELATION ION CHROMATOGRAPHY

A highly sensitive method of simultaneous separation and determination of Pb2+, Cu2+, Cd2+, Co2+, and Ni2+ was developed and evaluated by on-line sample pretreatment of chelation ion chromatography. Bulk quantities of anions, alkali metals, alkaline earth metals, tervalence cations, and other interfering components were eliminated by pyrophosphoric acid / ammonium acetate buffer solution (pH 5.5), while retaining heavy and transition metals on iminodiacetate-based resins. Then, they were disabsorbed and transferred to sulfonated cation exchangers. Finally, the concentrated trace metals were separated on a bifunctional ion exchange column by a concentration gradient of oxalic acid and sodium nitrate eluents, coupled with post-column sepectrophotometric detection with 2-[(5-bromo-2-pyridyl)-azo]-5-diethyl-aminophenol (5-Br-PADAP) at 560 nm. The method detection limits (signal-to-noise 3:1) were at or below μg L−1 levels. This technique was validated by analyzing standard biological references.

Alkylphenol reagents for the oil and gas industry

The efficiency of well drilling, oil and gas production, industrial refining of the feedstock produced, inhibition of corrosion of the equipment, etc., is determined to a significant degree by regulation of phase and energy interactions when they are conducted with chemical reagents having the properties of surfactants (SF) [1, 2]. Hydrocarbon (lipophilic) and highly polar (hydrophilic) groups are combined in SF molecules and their competition is characterized by the value of the hydrophilic-lipophilic balance (HLB) [3]. Many types of SF (Table 1) are synthesized from alkylphenols with an alkyl group of 6 - 20 carbon atoms; the proportion of these SF is ~40%. Their properties and efficiency are a function of both the nature of the highly polar groups (ethoxy, sulfo groups, amino groups, etc.) and the structure of the hydrocarbon part of the molecules. When an alkyl group in the aromatic ring of the alkylphenol molecule is in the para position, the degree of symmetry of the molecules and their tendency to aggregate into micelles increase (the bulk properties of solutions of SF improve); on the other hand, in the ortho position, micellization of the molecules is slowed so that the surface activity of the SF solutions is intensified [3]. We found that the predominant position of the alkyl group is determined by the structure of the olefin and the reaction conditions in alkylphenols obtained by the reaction of olefins with phenol in the presence of an acid catalyst -- KU-2 sulfonic cation-exchanger or p-toluenesulfonic acid (TSA) (Table 2). KU-2 sulfonic cation-exchanger, a solid sulfonic acid polymer in comparison to TSA, which is soluble in the reaction mixture, favors formation ofp-alkylphenols from olefins of both linear and branched structure to a greater degree, although with a lower total yield. However, this catalyst, in contrast to TSA, allows easily organizing production of alkylphenols in continuous flow conditions with the total yield increased to 80% and higher. In organizing production of alkylphenols based on isobutene and its dimers in domestic refineries with this technology, its

Styrene sulfonate cation exchange membrane

Styrene sulfonate cation exchange membrane