Activity of metal chromate and phosphate supported on ion‐exchange resins toward hydrogen peroxide decomposition

The mixed resins, Dowex MR‐3 and MR‐12, in the H⁺/Cl⁻ form, and the cation resin, Dowex‐50W, in the H⁺ form, were used as a support for some metal chromate and phosphate salts. Similarly, anionic resin, Amberlite IRA‐400, in the Cl⁻ form, was used as a support for some metal chromate salts. The activity of these metal salt‐supported on four different resins toward hydrogen peroxide decomposition was investigated. The decomposition of H₂O₂, with these catalysts, was found to follow first‐order kinetics with respect to [H₂O₂]. Factors that affected the rate of reaction, such as mesh size of the support, amount of supported salt, and the electrostatic interactions, were investigated. With Ag(I)‐chromate supported on mixed resin MR‐3 in the Ag⁺/NO₃⁻ form, the rate of reaction was greater than that with the mixed resin MR‐12 in the same form. Moreover, the rate with Ag(I) chromate supported on the anion resin IRA‐400 in the R‐NO₃⁻ form was greater than mixed resins. Also, the rate with Fe(III) chromate supported on Amberlite IRA‐400 in the R‐CrO₄²⁻ form was greater than other counter‐anionic forms as well as Dowex‐50W resin in the metal ion form. However, Fe(III)‐chromate supported on cation resin R‐Fe³⁺ showed greater activity than other cationic forms. On the other hand, the rate with MR‐3 resin in the Na⁺/PO₄³⁻ form was greater than that in the presence of supported Fe(III) phosphate. However, the rate of reaction increased when Fe(III) was replaced by Ba(II). Iron(III) phosphate supported on Dowex‐50W resin in the Na⁺ form showed greater activity compared to MR‐3 resin in the Na⁺/PO₄³⁻ form. In the case of Fe(III) phosphate supported on mixed resin MR‐12, the rate was much greater than that with unsupported resin. However, when Ba(II) phosphate was incorporated instead of Fe(III) phosphate, the rate of reaction increased considerably. The activity of Fe(III) chromate is greater than that of Fe(III) phosphate supported on the same cation resin. Activation parameters were evaluated and a probable reaction mechanism was proposed. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 667–675, 2000     

Mechanism of simultaneous removal of Ca2+, Ni2+, Pb2+ and Al3+ ions from aqueous solutions using Purolite® S930 ion exchange resin

The sorption mechanism of Ca²⁺, Ni²⁺, Pb²⁺, and Al³⁺on ion exchange resin S930 has been studied as a function of pH in both mono-component and quaternary systems at ion ratio 1:1:1:1. The equilibrium of ion exchange process in mono-component systems has been followed as an adsorption process and it was tested for Langmuir and Freundlich isotherm equations. The selectivity coefficient of the resin for these cations varied in different manners depending on the pH range. The structural characteristics of pores in the initial resin and the resin after contact with synthetic solutions at pH 3.03 and 3.95 have been investigated by using SEM and EDAX techniques.     

Sorption investigation on the removal of metal ions from aqueous solutions using chelating terpolymer resin

A novel chelating terpolymer resin has been synthesized from anthranilic acid, phenylhydrazine, and formaldehyde by condensation in glacial acetic acid. The structure of the chelating resin was clearly elucidated by use of a variety of spectral techniques, for example FTIR, and ¹H and ¹³C NMR spectroscopy. The average molecular weight of the terpolymer resin was determined by gel-permeation chromatography. The empirical formula and empirical weight of the resin were determined by elemental analysis. The physicochemical properties of the terpolymer resin were determined. Scanning electron microscopy was used to establish the surface features of the chelating resin. The ion-exchange behaviour of the resin for specific metal ions, viz. Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, and Pb²⁺, was evaluated by a batch equilibrium method. The study was extended to three variations: evaluation of metal ion uptake in the presence of different electrolytes at different concentrations; evaluation of metal ion uptake at different pH; and evaluation of metal ion uptake at different times. Further, the reusability of the resin was also determined to assess the efficiency of the resin after a few cycles of sorption. From the results it was observed that the resin acts as an effective chelating ion-exchanger.     

Synthesis of chitosan resin possessing 3,4-diamino benzoic acid moiety for the collection/concentration of arsenic and selenium in water samples and their measurement by inductively coupled plasma-mass spectrometry

A chitosan resin functionalized with 3,4-diamino benzoic acid (CCTS-DBA resin) was newly synthesized by using a cross-linked chitosan (CCTS) as base material. The adsorption behavior of trace amounts of elements on the CCTS-DBA resin was examined by the pretreatment with a mini-column and measurement of the elements by inductively coupled plasma-Mass spectrometry (ICP-MS). Arsenic(V) could be retained on the CCTS-DBA resin at pH 3 as an oxoanion of H₂AsO₄⁻. Selenium(VI) is strongly adsorbed at pH 2 and pH 3 as an oxoanion of SeO₄²⁻, while selenium(IV) as HSeO₃⁻ is adsorbed on the resin at pH 3. The sorption capacities are 82, 64, and 88 mg g⁻¹resin for As(V), Se(IV), and Se(VI), respectively. The effect of common anions and cations on the adsorption of As(V), Se(IV), and Se(VI) were studied; there was no interference from such anionic matrices as chloride, sulfate, phosphate, and nitrate up to 20 ppm, as well as from such artificial river water matrices as Na, K, Mg, and Ca after passing samples through the mini-column containing the resin. The CCTS-DBA resin was applied to the collection of arsenic and selenium species in bottled drinking water, tap water, and river water.     

Functionalization of chitosan with 3,4-dihydroxybenzoic acid for the adsorption/collection of uranium in water samples and its determination by inductively coupled plasma-mass spectrometry

A chitosan resin derivatized with 3,4-dihydroxybenzoic acid moiety (CCTS-DHBA resin) was newly synthesized for the collection/concentration of trace uranium by using cross-linked chitosan (CCTS) as base material, and the adsorption behavior of uranium as well as 60 elements on the resin was examined by passing the sample solutions through a mini-column packed with the resin. After the elution of the collected elements on the resin with 1 M HNO₃, the eluates were measured by inductively coupled plasma-mass spectrometry (ICP-MS).The CCTS-DHBA resin can adsorb several metal cations and several oxoanionic elements at appropriate pH. Among these metal ions, uranium shows an excellent adsorption behavior on this resin. Uranium as UO₂²⁺ species can be adsorbed on the resin by chelating mechanism with adsorption capacity of 330 mg g⁻¹ resin. Through the column treatment, the complete removal of large amounts of alkali and alkaline earth matrices without any loss of adsorption efficiency over prolonged usage were achieved with this resin.The CCTS-DHBA resin was applied to the adsorption/collection of uranium in tap water, river water and seawater samples with satisfactory results. The validation of the proposed method was carried out by analyzing uranium in the standard reference materials of SLRS-4, CASS-4, and NASS-5 after passing through the CCTS-DHBA resin, and the results showed good agreement with the certified values.     

Separation of rare earth and transplutonium elements by displacement chromatography on KU-2 cation exchange resin in the Cu2+ form under ionizing radiation

Changes in chromatographic parameters (pH, REE concentration, eluent concentration, separation coefficients) under irradiation using the KU-2 cation exchange resin in the Cu²⁺ form are studied experimentally and theoretically depending on the absorbed dose and respective destruction of the eluent. It is found that the use of the cation exchange resin in the Cu²⁺ form in the field of ionizing radiation leads to a more effective separation of REEs than in the case of using the Zn²⁺ and H⁺ forms of cation exchange resin.     

Selective separation of uranium using trimethylammonium acetosalycoylhydrazone modified Duolite C20 resin</p> </p>

Summary Duolite C20 resin modified with trimethylammonium acetosalycoylhydrazone has been developed, for the selective separation and/or preconcentration of uranium. The modified resin was characterized by elemental analysis and infrared spectra. Batch and column modes were applied. The newly designed resin quantitatively sorbs uranium ion at pH 3 when the flow rate equals to 2 ml ^. min ^-1 . The sorption capacity was 0.750 mmol ^. g^-1 for uranium ion, whereas its preconcentration factor was 200. The lower limit of detection was 5 ng ^. ml^-1 and its desorption was effective with 5 ml of 3 mol ^. l^-1 HCl or HNO₃ prior to detection spectrophotometry. The modified resin was highly ion-selective in nature even in the presence of large concentrations of electrolyte or organic media, with a preconcentrating ability for uranium ion. The modified resin was tested on its utility with synthetic, real and certified ore samples, showed RSD values of <2% reflecting the accuracy and reproducibility of the newly modified resin.</p> </p>     

Fibers and fiber cocktails to improve fire resistance of concrete

Hybrid organic–inorganic resin matrix, i.e., hexa[3,4-dicyano]-phenyl phosphonitrile trimer (HPPT) has been prepared by the reaction of hexachlorophosphonitrile and 4-hydroxyphthalonitrile in the presence of sodium hydride which on heating at 300 °C yielded a high-temperature-stable highly crosslinked hybrid resin (C-HPPT). The elemental analysis (C, H, and N), FTIR, and ¹H and ¹³C-NMR studies were used to characterize the synthesized hybrid resin. The thermal analysis studies viz. TG and DSC were also carried out to determine the thermal stability and glass transition temperature of the cured resin. The isothermal study of the cured resin after 300 h at 300 °C showed only a mass loss of 4.36%.     

Surface‐initiated ring‐opening polymerization of p‐dioxanone on Wang resin bead

Biodegradable poly(p‐dioxanone) (PPDO) was formed on Wang resin surface by surface‐initiated ring‐opening polymerization (SI‐ROP). The SI‐ROP of p‐dioxanone (PDO) was achieved by heating a mixture of Tin(II) bis(2‐ethylhexanoate) [Sn(Oct)₂], hydroxyl functionalized Wang resin, and PDO in anhydrous toluene at 80 °C. The resultant polymer‐grafted Wang resin (Wang‐g‐PPDO) was characterized by fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), optical microscopy (OM), and field‐emission scanning electron microscopy (FE‐SEM). The FTIR spectra of Wang‐g‐PPDO show peak characteristic of PPDO at 2943 cm^?1 (? C? H stretch), at 1741 cm^?1 (? C?O stretch), and 1136 cm^?1 (C? O? C stretch) indicating the formation of ester linkage between PPDO and hydroxyl terminated Wang resin. The DSC thermogram show melting peak corresponding to PPDO polymer on Wang resin surface. Thermogravimetric investigation shows increase in PPDO content on the Wang resin surface in terms of percentage of weight loss with increase in reaction time. The OM and SEM photographs clearly show the formation of PPDO polymer on the Wang resin surface without altering the spherical nature of Wang resin bead. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1178–1184, 2008     

Determination of uranium in sea water by preconcentration on Chelex 100 and neutron activation

Trace amount of uranium in sea water was preconcentrated on Chelex 100 chelating resin. The resin was directly applied as a support for irradiation.²³⁹U was selectively and quantitatively recovered from the irradiated resin by elution, using 1.0M sodium carbonate solution as eluant. γ-Ray spectrum was measured with a Ge(Li) detector.     

Synthesis of cross-linked chitosan possessing N-methyl-d-glucamine moiety (CCTS-NMDG) for adsorption/concentration of boron in water samples and its accurate measurement by ICP-MS and ICP-AES

A chitosan resin derivatized with N-methyl-d-glucamine (CCTS-NMDG) was synthesized by using a cross-linked chitosan (CCTS) as base material. The N-methyl-d-glucamine (NMDG) moiety was attached to the amino group of CCTS through the arm of chloromethyloxirane. The adsorption behavior of 59 elements on the synthesized resin was systematically examined by using the resin packed in a mini-column, passing water samples through it and measuring the adsorbed elements in eluates by ICP-MS. The CCTS-NMDG resin shows high ability in boron sorption with the capacity of 0.61 mmol ml⁻¹ (= 2.1 mmol g⁻¹). The sorption kinetics of this resin was faster than that of the commercially available resins. Other advantages of the synthesized resin are: (1) quantitative collection of boron at neutral pH regions; (2) complete removal of large amounts of matrices; (3) no loss of efficiency over prolonged usage; (4) effective collection of boron in wide range concentration using a mini column containing 1 ml resin; (5) complete elution of boron with 1 mol l⁻¹ nitric acid. The resin was applied to the collection/concentration of boron in water samples. Boron in tap water and river water was found to be in the range of 6-8 μg l⁻¹. The limit of detection (LOD) of boron after pretreatment with CCTS-NMDG resin and measurement by ICP-MS was 0.07 μg l⁻¹ and the limit of quantification (LOQ) was 0.14 μg l⁻¹ when the volume of each sample and eluent was 10 ml.     

Determination of 232Th in seawater by ICP-MS after preconcentration and separation using a chelating resin

This article describes an analytical method for the separation, preconcentration and determination of ²³²Th in seawater samples at sub-ng/L levels using a NOBIAS CHELATE PA1 resin and a sector field (SF) inductively coupled plasma mass spectrometer (ICP-MS). The resin showed excellent adsorption of ²³²Th at a low pH of 2.4 ± 0.4 in a relatively small volume (200 mL) of seawater. ²³²Th adsorbed on the resin was easily eluted using 5 mL of 0.8 M HNO₃. An enrichment factor of 40 was achieved for ²³²Th analysis. Ethylenediamine-tetraacetic acid disodium salt dehydrate (EDTA) was used to investigate the effect of ²³²Th-binding organic ligand on the retention of ²³²Th on the chelating resin. Results obtained using acidified samples (pH of 2.4 ± 0.4) showed EDTA had no significant effect on ²³²Th recovery, indicating that at this low pH, ²³²Th was dissociated from the ²³²Th-binding organic ligand and quantitatively retained on the NOBIAS CHELATE PA1 resin. The developed analytical method was characterized by a separation and preconcentration taking approximately 4 h and a low detection limit of 0.0038 ng/L for ²³²Th, and was successfully applied to the determination of ²³²Th in seawater samples collected from coastal areas, Japan.     

Discriminating Amino Resin Paints From Alkyd Resin Paints with Two Kinds of Pigments in Automotive Coatings in Forensic Analysis by FTIR Spectroscopy

The analysis of automotive coatings is important to forensic scientists, especially in the investigation of hit-and-run accidents. Amino resin paints, alkyd resin paints, and polyurethane paints are all popular automotive coatings. In this study, FTIR was employed to investigate these coatings, particular in amino resin paints. IR spectra were tentatively interpreted. The indicative peaks distinguishing amino resin paints (1550 cm^?1) and alkyd resin paints (1600 cm^?1/1580 cm^?1) were summarized. Two kinds of alkyd resin paints (with the Pigment Scarlet Powder and with the Toluidine Red), which were frequently confronted in cases and might readily be read as amino resin paints in IR spectra, were studied and interpreted. The indicative peaks (1619 cm^?1, 776 cm^?1 and 1674 cm^?1, 1494 cm^?1) were selected to discriminate these two kinds of alkyd resin paints from amino resin paints and avoid an incorrect certificate of authenticity. The data in this study can help the forensic scientists identify these three paints accurately, especially in the cases with the interference of the pigments.     

Synthetic functionalized terpolymeric resin for the removal of hazardous metal ions: synthesis,characterization and batch separation analysis

An effectual functionalized synthetic resin involving anthranilic acid/4‐nitroaniline/formaldehyde was synthesized for the detoxification of hazardous metal ions. The resin was characterized by Fourier transform infrared, ¹H, and ¹³C nuclear magnetic resonance spectroscopy, and its morphology was established through scanning electron microscope and X‐ray diffraction. The resin was analyzed by thermogravimetric analysis to assess the thermal stability, in which the resin could be used in high temperature aqueous solutions for the elimination of harmful metal ions. The ion‐exchange property of the resin was evaluated by batch technique for specific metal ions viz. Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, and Pb²⁺. The study was extended to three variations such as effect of metal ion uptake in the presence of various electrolytes in different concentrations, effect of pH, and effect of contact time. The outcome proved that the resin can be used as a strong cation‐exchanger to remove various metal ions from the solutions. The resin could be regenerated and reused with quantitative recovery of metal ions for few cycles. On comparison with the earlier reported resins, the synthesized resin has found excellent capability of metal ion recovery. The resin possesses an utmost ion‐exchange capacity, which is in good harmony with isotherm models and kinetics. Copyright © 2015 John Wiley & Sons, Ltd.     

The separation of99Tc from mixed fission products and its determination by neutron activation

Technetium is separated from the bulk of fission products and other elements in dissolved nuclear fuel by a ferric hydroxide precipitation followed by filtration and loading of the filtrate on an anion exchange resin. The technetium remains on the resin presumably as pertechnate ion. The resin is exposed to a neutron flux in a nuclear reactor activating⁹⁹Tc to¹⁰⁰Tc which decays with the emission of a 539keV gamma-ray with a 15.8 second half-life. This gamma-ray is conveniently counted with conventional solid state techniques.Work performed under contract to the U. S. Department of Energy under contract number DE-ACO7-76IDO1570.     

Macroporous anion exchanger purolite A-500 loaded with ferron for palladium(II) recovery

A systematic study on interaction of Pd(II) with 7-iodo-8-hydroxyquinoline-5 sulfonic acid (Ferron) and the strongly basic anion exchange resin Purolite A-500 in its chloride form was carried out. It was found that for Ferron/resin ratio ranging from 0.15 to 0.70 mmol g-1, the retention of chelating reagent on the investigated ion exchanger is practically quantitative. The sorption increase of Pd(II) on Ferron-loaded resin was observed for higher values of parameters like: pH solution, initial concentration and temperature. It was observed that the equilibrium distribution of Pd(II) between sorbent and solution could adequately be described by the Langmuir model with two parameters. The thermodynamic quantities characteristic of Pd(II) sorption process (ΔG = -18.4 kJ mol^-1; ΔH = 11.7 kJ mol^-1; ΔS = 104.4 J mol^-1 K^-1) suggest a strong affinity between Ferron-loaded resin and the tested cation.     

Influence of the settling of the resin beads on diffusion gradients in thin films measurements

Binding resin beads used in DGT (diffusion gradients in thin films) tend to settle to one side of the resin during casting. This phenomenon might be relevant for metal accumulation when partially labile complexes dominate the metal speciation, especially after recognizing the important role played by complex dissociation in the resin domain. The influence of the inhomogeneity of the binding agent distribution on metal accumulation is here assessed by numerical simulation of DGT devices with binding beads in only one half of the resin disc, as a reasonable model of the standard resin discs. Results indicate that a decrease in mass accumulation of less than 13% can arise in these inhomogeneous devices (as compared with an ideal disc with homogeneous dispersion of the resin beads) when complexes with stability constant K < 10² m³ mol⁻¹ (K < 10⁵ L mol⁻¹) dominate the metal speciation. The loss increases as K increases, but the percentage of mass loss always remains lower than the volume fraction of resin disc without beads. For very labile or inert complexes, the impact of the inhomogeneous distribution of binding resin beads is negligible. As kinetic dissociation constants of complexes can be estimated from the distribution of the metal accumulation in a DGT device with a stack of two resin discs, the influence of the inhomogeneity on the recovered kinetic constant is also assessed. For the cases studied, the recovered kinetic dissociation constant, k_d,recovered, retains the correct order of magnitude, being related to the true k_d by k_d ≈ f⁻¹ k_d,recovered, quite independently of K and k_d values, being f the fraction of volume of the resin disc where resin beads are dispersed.     

Separation of lithium isotopes with the N3O2 trimerrifield peptide resin

A study on the separation of lithium isotopes was carried out with 1,13-dioxa-4,7,10-triazacyclopentadecane-4,7,10-trimerrifield peptide resin [N₃O₂3M]. The resin having N₃O₂ as an anchor group has a capacity of 0.2 meq/g dry resin. Upon column chromatography [0.1 cm (I.D)×30 cm (height)] using 1.0M NH₄Cl solution as an eluent, a single separation factor of 1.00104 was obtained from the elution curve and isotope ratios based on theGlueckauf theory. The heavier isotope,⁷Li concentrated in the resin phase, while the lighter isotope,⁶Li enriched in the solution phase.     

Separation of lithium isotopes by NDOE bonded Merrifield peptide resin

The novel NDOE (1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane) ion exchange resin was prepared. The ion exchange capacity of NDOE azacrown ion exchanger was 0.2 meq/g dry resin. A study on the separation of lithium isotopes was carried out with NDOE novel azacrown ion exchange resin. The lighter isotope,⁶Li concentrated in the solution phase, while the heavier isotope,⁷Li is enriched in the resin phase. By column chromatography (0.1 cm I.D.×32 cm height) using 2.0M NH₄Cl as an eluent, a separation factor,a=1.0201 was obtained.