Cation-exchange Material Research Articles

Preparation and Characterization of Pore Filled Hybrid Composite Membrane Composed of Cation Exchange Materials and Polyethylene Support.

This study investigated ion exchange membranes for application to seawater desalination processes. This can provide better energy efficiency than the conventional reverse osmosis process. In this experiment, the problem of decreasing ion exchange performance when the ion exchange composite membrane was prepared could be improved through nanoparticles. The nanoparticle added ion exchange hybrid membrane showed ion exchange capacity similar to that of the conventional pristine film. In addition, the polymer having a high ion exchange capacity has poor mechanical strength, but has excellent mechanical strength of 30 MPa or more by the introduction of a polyethylene support.

Preparation of a PVDF/PVDF-g-(PSSS-co-PAA) graft copolymerization-blending cation exchange material and effects of the synthesis method on the material structures and properties

Preparation of a PVDF/PVDF-g-(PSSS-co-PAA) graft copolymerization-blending cation exchange material and effects of the synthesis method on the material structures and properties

Removal of biogenic amines from wines by chemisorption on functionalized silica and effects on other wine components

The effectiveness of several functionalized silica materials (cation-exchange materials) for the removal of biogenic amines from wines, and the effects on other wine components and organoleptic characteristics were evaluated. Results have shown that mesoporous silica material bi-functionalized with phosphonic and sulfonic acids allowed the removal of histamine, putrescine, cadaverine, spermine and spermidine from wines, although the dose must be adapted for each wine according to the removal requirements and wine characteristics. A plus of the adsorbent developed is that it can be recovered and re-used for at least 3 treatments. Immediately following the treatments, a decrease in the levels of linear ethyl esters (ethyl hexanoate, ethyl octanoate and ethyl decanoate) was observed, although these levels were re-equilibrated after several days reducing this undesired side effect. A slight, but perceptible, effect on wine color was observed, probably due to the slight decrease in the pH of the wine produced by the treatments. On the basis of the sensory analysis that focused only on the aroma of the wines, the proposed technique would be more adequate for wines aged in barrels than for young wines.

Polyurethane nanocomposites can increase the release control in granulated fertilizers by controlling nutrient diffusion

We proposed a nanocomposite system based on castor oil-derived polyurethane (PU) for controlling the release of fertilizers by an ion-exchange mechanism. PU coatings modified with less than 5% montmorillonite, a cation-exchange material, successfully retarded the nitrogen release from urea granules, with less than 50% of the nutrient released within 18 days of immersion, as confirmed by soil incubation experiments. The same profile was observed for the phosphate release from monoammonium phosphate (MAP) granules coated with PU modified with hydrotalcite (less than 5% by weight), an anion-exchange material. The release times were proportional to the contents of the cation- or anion-exchange materials, which exhibited specific correlations with the kind of nutrient released (i.e., cationic or anionic), confirming the diffusion barrier promoted by the PU coating structures. Our results demonstrated that the use of PU nanocomposites can significantly reduce the coating thickness with improved nitrogen and phosphorus release control, opening a new field for the investigation of controlled release fertilizers.

Microwave Irradiation-Assisted Synthesis of Zeolites from Coal Fly Ash: An Optimization Study for a Sustainable and Efficient Production Process.

Class F South African coal fly ash was used as a precursor for the synthesis of zeolite A via complete microwave irradiation. To attain optimal conditions for the synthesis of zeolite A with minimum impurities, the microwave synthesis time, irradiation power, and Si/Al ratio were varied. Sodalite with fly ash phases were obtained when the Si/Al ratio in the coal fly ash was not adjusted and when the microwave irradiated coal fly ash slurry was used instead of the extract solution. Increased microwave irradiation time power and time favored the crystallization of zeolite A phase due to sufficient energy needed to ensure the dissolution of Al and Si from coal fly ash. A Brunauer–Emmett–Teller surface area of 29.54 m2/g and a cation exchange capacity of 3.10 mequiv/g were achieved for zeolite A, suggesting its potential application as an adsorbent and cation exchange material for environmental remediation. Complete microwave irradiation offers a greener approach toward zeolite synthesis from coal fly ash compared to conventional hydrothermal and fusion methods that consume a lot of energy and require longer reaction times.

Column Classification/Characterisation of Strong Cation Exchange Phases for the Liquid Chromatographic Analysis of Small Molecular Weight Bases

A simple, rapid and robust protocol for the characterisation of strong cation exchange columns for the analysis of small molecular weight bases is described. A range of ten different phases were characterised, and the resultant selectivity and retention factors analysed using Principal Component Analysis. The score plots for the first and second principal components described 83% of the variability within the dataset. Score plots highlighted the large chromatographic differences observed between the phases, the validity of which was established using a larger range of bases. All the strong cation exchange materials demonstrated a synergistic mixed mode (i.e. ion exchange and hydrophobic) retention mechanism. Principal Component Analysis also highlighted the potential difficulty in locating suitable strong cation exchange “back-up” columns for the analysis of small molecular weight bases in that the characterised columns all displayed very different selectivities. The robustness of the protocol was confirmed by a factorial design experiment.

Studies on polyoxyethylene octyl phenyl ether supported thorium(IV) phosphates: a new cation exchange material

A new surfactant supported cation exchanger and adsorbent named, polyoxyethylene octyl phenyl ether supported thorium(IV) phosphate (TX-100ThP) has been reported along with its synthesis, physico-chemical characterization such as scanning electron microscopy, X-ray diffraction, thermogravimetric analysis–differential thermal analysis and Fourier transform infra-red study. Following the characterization, the formed product has been tested for its efficiency in ion exchange chemistry and in analytical chemistry. For the testing, adsorption of alkaline earths—Mg2+, Ca2+, Sr2+ and Ba2+ and transition metal ions such as Fe3+, Mn2+, Ni2+, Cd2+, Co2+, Cu2+, Hg2+ and Pb2+ have been explored in different acidic media and the results revealed the selectivity of synthesized material towards Hg2+ ions. On that basis, the material has been used to treat the binary laboratory-made samples, exploring the environmental importance of the cation exchanger in material science.

Sensitizing, sensing and chemical separation of Tb(III) ions: All in a novel copper metal-organic framework

The importance of rare earth elements in high-tech materials has promoted the necessity to develop new materials for sensing and separating them. Luminescent metal-organic frameworks (MOFs) due to their promising applications as functional materials for chemical sensing and separation, which upon introducing analytes create multi-responsive systems, have been receiving great attention by scientists. In this regard, we have designed and synthesized a novel three-dimensional copper framework, [Cu2(3,4-pydc)2(H2O)5]n.2nH2O (1; 3,4-H2pydc = 3,4-pyridine dicarboxylic acid), in ambient condition with an interesting topology and potential application as a cation exchange material. Upon Tb3+ ions uptake, compound 1 exhibited the antenna effect to sensitize Tb3+ ions and its fluorescent emission was enhanced. It also showed selective sensing ability based on turn-on fluorescence response towards Tb3+ ions, in a mixture of main and transition metal ions and Tb3+ ions. Furthermore, the results showed that the Tb3+ ion exchange process is reversible. Therefore, compound 1 is a promising multifunctional luminescent MOF for simultaneous sensing and chemical separation of Tb3+ ions which is an advantage over the previously used MOFs in this regard. Furthermore, the reusability experiment demonstrated that 1 can be utilized for long-term detection and separation of Tb3+ ions.

Effect of Nanodisperse Iron and Nickel Oxides on the Structure and Properties of Novolac Phenol—Formaldehyde Polycon Cation-Exchange Materials

Several aspects of the synthesis and formation of a sulfonated cation-exchange matrix on the surface and in the structure of novolac phenol—formaldehyde fiber with nanodisperse iron and nickel oxides added to the monomer composition were examined.

A comparative study of ion exchange behavior and analytical applications of zirconium and tin based polyaniline hybrid cation exchangers

The present work reports the synthesis, characterization and ion exchange properties of polyaniline based hybrid cation exchangers such as polyaniline‑zirconium(IV) tungstate (PA/ZrW), polyaniline‑zirconium(IV) tungstomolybdate (PA/ZrWMo), polyaniline‑tin zirconium molybdate (PA/SnZrMo) and polyaniline‑tin cerium molybdate (PA/SnCeMo). The structural characterization and morphology of the hybrid cation exchangers were done by FT-IR, XRD, SEM-EDS and UV–Vis studies. Thermal stability of hybrid cation exchangers was analyzed by TGA study. The order of ion exchange capacity for alkali and alkaline earth metal ions on the synthesized hybrid materials was found to be in the sequence K+ > Na+ > Li+ for alkali metals and Ba2+ > Sr2+ > Ca2+ > Mg2+ for alkaline earth metals. The distribution coefficient of metal ions in de-mineralized water and different concentrations of HNO3, effect of pH, adsorbent dose, drying temperature and concentration of Pb2+ on Kd value were also investigated. It is clear from the distribution studies that all the hybrid cation exchange materials have more selectivity towards toxic metal ion, Pb2+ and Cd2+ and least affinity towards Zn2+, Co2+, Cu2+, Mg2+ and Ni2+ ions.

Role of preparation technique in the morphological structures of innovative nano-cation exchange

Nano-zirconium tungsto-vanadate cation exchange material was constructed in different morphological structures using sol–gel, hydrothermal and microwave techniques in presence of polymeric matrix as stabilizing agent. Polyvinyl alcohol was established as the optimum stabilizing agent. Influence of preparation parameters in presence of polyvinyl alcohol was examined as a function of ion exchange capacity and surface area for the prepared materials. The optimum reactant molar ratio was recorded as 1:0.5:1 for zirconium:vanadium:tungsten respectively. Properties of the most efficient ion exchange samples were inspected using X-ray diffractometer (XRD), thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). The feasibility of the prepared materials as cation exchanger for lead and strontium decontaminations was compared. Microwave represented the most efficient technique for material production with highest surface area of 671m2/g and highest ion exchange capacity of 4.7meq/g and about 64.9 and 44.2mg/g lead and strontium sorption capacity respectively.

Evaluation of ion exchange material from sulfonated polystyrene waste synthesized for removal Cr3+ from aqueous solution by column experiment

The paper aims to study the effect of operating conditions in the column experiment with the ion exchange material which was prepared in optimum synthesized conditions. Polystyrene waste from disposable food packaging was dissolved in cyclohexane and sulfonated by sulfuric acid to synthesize cation exchange materials which were applied to remove Cr3+ in water by the ion exchange principle. The optimum conditions for this method were found out and described in previously published literature of the author. Characterization by SEM and Fourier Transforms Infrared (FT-IR) spectroscopy proved that the additional Sulfonic groups were presented. The efficiency of Cr3+ removal was highly affected by column bed height, initial ion concentrations and flow rate of effluent. The highest efficiency of material was 84.0% with a material bed height of 10 cm in the removal of Cr3+ from simulated wastewater containing initial Cr3+ concentration of 120 mg/l. The experimental data obtained from this study was consistent with Thomas and Yoon-Nelson kinetic models, which will be applied for column design in practical study and design. The results from this method can help reduce the plastic waste and easy to apply in practice for removal of Cr3+ in wastewater.
 Keywords: ion exchange; polystyrene waste; synthesize; chromium.

Selective removal of lead (II) ions and estimation of Ca (II) ions using poly-o-toluidine–zirconium (IV) molybdophosphate

A new composite cation exchange material poly-o-toluidine–zirconium (IV) molybdophosphate (PTD–ZrMoP) was synthesized by sol–gel method through the incorporation of inorganic gel of zirconium(IV) molybdophosphate in the organic polymer poly-o-toluidine. The PTD–ZrMoP was characterized by FTIR, FESEM, HRTEM, XRD and TGA/DTA techniques. Elution behavior, thermal stability, pH titrations, chemical stability, distribution studies and quantitative separation of metal ions in binary synthetic mixtures and real life samples on nanocomposite ion exchanger were also investigated. The ion-exchange capacity of the nanocomposite ion exchanger (0.84 meq/g) has been observed to be higher compared to that of its inorganic counterpart (0.49 meq/g). The nanocomposite was found to be thermally stable and retained 71.43% of its ion-exchange capacity up to 300 °C temperature. The environmental applicability of the PTD–ZrMoP nanocomposite was explored by achieving binary separations and selective separation of Pb2+ from synthetic mixtures of metal ions. The analytical utility of nanocomposite ion exchanger has been established by the separation of harmful Pb2+ ions from waste water samples obtained from paint industry, textile industry and lead storage battery unit, and by the quantitative estimation of Ca2+ ions in a commercially available pharmaceutical formula.

Sulfonated polystyrene waste in liquid phase as on-exchange material to remove Cr (III) in aqueous solution

Polystyrene waste from disposal products has been sulfonated in a homogeneous phase by using sulfur acid and cyclohexane to synthesize cation exchange material, which could be used to uptake Cr(III) from aqueous solution. In this study, by analysis techniques such as SEM (Scanning Electron Microscope) and FITR (Fourier transform infrared), the surface area of material groups is revealed that they are larger than raw materials to increase point of contact with Cr(III). Moreover, it is proven that the additional sulfonic groups were presented. The results pointed out that the dependence of ion exchange column operation on many factors (size, reaction time, flow rate,…) exert an influence on the efficiency of Cr(III) ion treatment. In addition, experimental conditions which affect the sulfonation conversion, have been investigated such as temperature, modification time, H2SO4 concentration,… It was found that reducing the Cr(III)concentration by 87.51% and 98.72% for 10 cm and 15cm ion-exchange height layer after 3 hours operation in the reaction conversion using the column 8mm diameter, flow rate 2.00ml per minute with shaking speed 220 rpm. The experimental data were consistent with Thomas and Yoon-Nelson kinetic models. The ability of sulfonated waste polystyrene to uptake chromium ion from aqueous water has been evaluated significantly.

Purification of lysozyme from chicken egg white using diatom frustules

A nontoxic chromatographic matrix, with low cost and high adsorption capacity, is always a major goal for therapeutic protein purification. In this study, the frustules from two cultured diatoms, Nitzschia bilobata (AQ1) and Psammodictyon panduriforme (NP), were investigated as cation exchange materials for lysozyme purification from chicken egg white. The surface area and cation exchange capacity of frustules were about 400 m2/g and 140 μmol/mL for AQ1, 390 m2/g and 130 µmol/mL for NP. The optimal pH was 9 for adsorption. Through batch purification, the lysozyme recovery was 86% with a purity of 95% by AQ1 frustules, which was higher than that by NP frustules (82% with a purity of 90%). In the flow-through system, the purity using AQ1 frustules notably increased to 99%, higher than the result of 91% using NP frustules. Diatom frustules from AQ1 are more effective and could be an alternative chromatographic matrix for lysozyme purification.

Study of the Influence Exerted by Microscopic Additives of Fullerenes on the Absorbing Capacity of Cation-Exchange Resins for d-Elements in Aqueous Media

Introduction of fullerenes on the surface of KU-23 and KU-2-8 cation-exchange materials in amount of 0.001–0.005 wt % results in that the sorption capacity for copper cations becomes 1.2–1.6 times higher, and that for lead cations, 1.3–2.0 times higher. Ku-23 modified with fullerenes is characterized by a decrease in absorption capacity for Fe3+ cations by a factor of 1.3–2.0. Modification with fullerenes of ion-exchange materials leads to an increase by (10–12)% in the number of strong acid groups for all the materials under study and to a 1.2 times increase in the number of weak acid groups for KU-2-8. A mechanism is suggested for the sorption of metal cations on the fullerene-modified ion-exchange materials.

Rapid determination of lead ions using polyaniline-zirconium (IV) iodate -based ion selective electrode

Lead (II) is the hazardous and toxic material for human being and animals since it damages the central nervous system causing disorder of the circulatory system and brain. Hence to overcome the toxic effects of lead, rapid, simple and effective methods to detect Pb (II) is necessary. Pb (II) ISE membrane was prepared by the use of polyaniline-zirconium (IV) iodate composite cation-exchange material. To prepare this electrode, a solution casting method was used, and the prepared electrode was subjected to different characterisation techniques including SEM, XRD and FTIR. Outstanding results were obtained for properties such as porosity, thickness, water content, electrical conductivity and swelling. The membrane was found to have a working concentration ranging between 1 × 10−12 M and 1 × 10-1 M, and the Nernstian slope was obtained as 29.28 mV which lead to change in ion concentration. It showed good stability and can be used for six months without any deviance. The experimental studies showed that the response time is very fast, i.e. 10 s for lead ion concentration ranges from 1 × 10-8 to 1 × 10-1 M. It has been studied for concentration ranging at 1 × 10-1 M, and 1 × 10-3 M with a pH ranging between 2.5 and 6.5 and it was found to operate successfully. It exhibited good reproducibility as well as the detection limit.

Trimodal Mixed Mode Chromatography That Enables Efficient Offline Two-Dimensional Peptide Fractionation for Proteome Analysis.

Offline two-dimensional chromatography is a common means to achieve deep proteome coverage. To reduce sample complexity and dynamic range and to utilize mass spectrometer (MS) time efficiently, high chromatographic resolution of and good orthogonality between the two dimensions are needed. Ion exchange and high pH reversed phase chromatography are often used for this purpose. However, the former requires desalting to be MS-compatible, and the latter requires fraction pooling to create orthogonality. Here, we report an alternative first-dimension separation technique using a commercial trimodal phase incorporating polar embedded reversed phase, weak anion exchange, and strong cation exchange material. The column is capable of retaining polar and nonpolar peptides alike without noticeable breakthrough. It allows separating ordinary and TMT-labeled peptides under mild acidic conditions using an acetonitrile gradient. The direct MS compatibility of solvents and good orthogonality to online coupled C18 columns enable a straightforward workflow without fraction pooling and desalting while showing comparable performance to the other techniques. The method scales from low to high microgram sample quantity and is amenable to full automation. To demonstrate practical utility, we analyzed the proteomes of 10 human pancreatic cancer cell lines to a depth of >8,700 quantified proteins.

土壌吸着基の特性について(第1報) : 各種処理のC.E.C.に及ぼす影響

土壌吸着基の特性について(第1報) : 各種処理のC.E.C.に及ぼす影響

Properties of alkali-activated slag with addition of cation exchange material

The massive mobile alkali metal cations in alkali-activated slag (AAS) cements are significantly connected to the issues such as efflorescence, carbonation and potential alkali-aggregate reaction, and greatly restrict their extensive application and development. This paper attempts to use cation exchange materials to remove the freely moved alkali cations in AAS cements. Two representative cation exchange materials, vermiculite and 5A zeolite, were added at mass ratio of 5% and 10% to slag activated by sodium hydroxide. 5A zeolite showed a faster and stronger ions exchange capability to vermiculite in alkaline solution. However vermiculite immobilized more Na+ ions than 5A zeolite in AAS pastes, and the specimens with vermiculite displayed a higher compressive strength, attributed to generate more hydration products which were shown in XRD, TG-DSC and EDS tests, and formed a compact microstructure seen in SEM image. It is concluded that these two cation exchange materials could remarkably reduce the unrestrained alkali ions in the AAS cements, and the properties of AAS cements influenced by cation exchange materials are highly dependent on the category of the exchanged cations.