A novel and simple preparation method for ion-exchange material was proposed as an alternative for preparation of conventional ion-exchange resin based on styrene-divinyl-benzene matrix. A sulfonic acid group was readily introduced by radiation-induced cografting of sodium styrenesulfonate (SSS, CH₂=CHC₆H₄SO₃Na) with acrylic acid (AAc, CH₂=CHCOOH) to various shapes of trunk polymers made of polyethylene (PE), polypropylene (PP) and polytetrafluoroethylene (PTFE) . Immersion of the electron-beam-Irradiated PE membrane into the mixture of SSS and AAc for 12 h at 323 K provided a SO₃H density of 2.5 mol per kg of the H-type product, which is equivalent to that of a commercially available cation-exchange membrane.

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Most of the environmental samples have complex compositions. Hence the separation and preconcentration of analytes are essential for the accurate and precise determination of trace elements in environmental samples. Ion-exchange chromatography is an excellent technique which permits the selective separation by the appropriate combination of ion-exchanger and eluent. The present paper describes the analytical methods established for the determination of six trace elements (beryllium, tin, uranium, molybdenum, indium and bismuth) in silicates, biological materials or sea waters by using ion-exchange chromatographic separation and spectrophotometry or atomic absorption spectrometry.

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This study describes the dissolved state of colloidal silica in water and its adsorption properties on anion exchange resins (AERs) . A colloidal silica solution of 3% was prepared by ion exchange resin method from a sodium silicate solution. The colloidal silica in water formed about 10 nm particles in diameter. When leaving the colloidal silica solution at less than pH=7, the gelation was occurred. The gelation rate became the fastest at pH=5.2. The adsorption properties of colloidal silica on various AERs were .investigated in batch adsorption. When added strong base anion exchange resins (SBAERs) to the colloidal silica solutions of about 560 μg/mL as SiO₂, the colloidal silica concentration in water decreased rapidly, at the same time, ionic silica was newly generated on the resin surface. The total amounts of silica removed by SBAERs became larger than the stoichiometrically removable amount of ionic silica by them. According to the scanning electron microscopic observation, colloidal silica adsorbed on the surface of SBAERs became to dissolve to the resin inside with the elapse of time. These results suggest that colloidal silica adsorbed on SBAERs should exist in concentrated state inside of the resins and in ionic silica at the ion exchange sites.

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Rare-earth elements were electrically dialyzed in the cerium-gadolinium-yttrium solution and the cerium-lanthanum-praseodymium-neodymium solution in the presence of EDTA as a chelator. The rare-earth elements were finely separated into cerium and gadolinium-yttrium from their mixture and into cerium-lanthanum and praseo-dymium-neodymium from their mixture under the conditions of a wide range of their concentration fraction and their complexing ratio of 50%. The experimental results were successfully explained by a model based on the Nernst-Planck equation with the due consideration of solution equilibrium, membrane selectivity, and migration in the membrane. The model revealed that the separation efficiency was improved by the application of cascade electrodialysis and also that the rare-earth elements should be masked by the same amount of the complexing agent as that of the rare-earth element desired not to permeate through the membrane.

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Zirconium phosphates have recently occupied public attention as new materials with a unique pore structure. The compounds were classified by the element, the structure and the applied characters, and their preparation methods were abstracted. The basic physical properties of zirconium phosphate on the market were reported and their ionic exchange behaviors were investigated. From the results of relation between the ammonium ion and the hydrogen ion concentration and the exchange velocity, it made clearthe zirconium phosphate with the second-dimentional layer structure, γ-Zr (HPO₄) ₂⋅2H₂O, exceeded in the exchange activity and velocity.
For the examples of application, we reported an amorphous zirconium phosphate, Zr (HPO₄) ₂⋅nH₂O, used as an ammonium ion adsorbent and a three-dimentional network zirconium phosphate, HZr₂ (P0₄) ₃, as a fixative of Cs.

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