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Structure and ion exchange properties of crystalline antimonic acid
308 reagents to obtain various specific sorbents, ion exchange resins and polymer-supported reagents. Among the products were: anion-exchange resins having differentiated basicity and steric structures; selective cation exchangers; solid extractants that can serve as reaction media; electron-exchanging resins; oxidating and halogenating as well as disinfecting and bactericidal copolymers. Published in part in Reactive Polymers, 4 (1986) 311.
Joanna Surowiec, Technological Institute of Chemical and Food Industry, Wrodaw, Poland: Derivatographic Examinations of Poly(styrene-divinylbenzene)-type Cation Exchangers with Phosphorus-containing Functional Groups The thermal stability of organophosphorus cation exchangers obtained from styrene-divinylbenzene copolymers of Wofatit type was studied by means of T G - D T G - D T A techniques (in air or argon). Resins with gel and macroporous structure containing phosphinic or phosphonic acid functional groups, or both were examined. Relationships between the thermal characteristics, the kind of functional groups and the structure of the matrix were established. The activation energies of thermal degradation of the resin tested were calculated by the Horowitz-Metzger method. Comparative results for Wofatit commercial cation exchangers with -SO3H and - C O O H groups were also obtained. These proved to have higher thermal stability than the other phosphorus-containing cation exchangers. To be published in J. Therm. Anal.
S. Milesz and G. Lustyik, Isotope Laboratory, Kossuth Lajos University, and VILEG Laboratory, University Medical School of Debrecen, Debrecen, Hungary: Structure and Ion Exchange Properties of Crystalline Antimonic Acid Sorption properties, structure of crystalline antimonic acid and the mechanism of sorption were studied. For the measurements alkali metal ions and "static" labelling method were used. The particle size distribution curve of the sorbent was plotted by means of scanning electron micrographs of different enlargements. It shows that the major portion of the particles is of about 2 - 4 x 10 -5 m radius. Thus~ an expected fast sorption is characteristic of the system.
A Bilewicz, B. Barto~, H. Polkowska-Motrenko and J. Narbutt, Department of Radiochemistry and Department of Analytical Chemistry Institute of Nuclear Chemistry and Technology, Warsaw, Poland: New Composite Ion Exchanger--Hydrated Antimony Pentoxide in Phenolsulphonic Matrix--and its Application in Neutron Activation Analysis Crystalline antimony pentoxide (HAP), commonly used in neutron activation analysis for selective removal of sodium-24 ions from hydrochloric acid solutions of the irradiated samples, is not free from some substantial drawbacks; e.g., slow kinetics of the sorption process, irregular shape of the grains and low resistance of the material against hydrochloric acid even at high concentrations. In order to improve the properties of the sorbent, the powdered HAP was implanted into a matrix of a phenolsulphonic resin. The spherical beads of the composite sorbent obtained are characterized by good mechanical properties, high stability in hydrochloric acid solutions and improved kinetics of ion exchange. The distribution coefficient of Na + in 5 M HC1 for the composite sorbent containing 60% HAP ( K d = 2 × 103 cm3/g) is close to that for the pure crystalline HAP grains ( K d = 3 x 1 0 2 cm3/g). The HAP composite ion exchanger was used for the determination of Cu and Mn in biological materials. Accepted for publication in Anal. Chem.
Joanna Surowiec, Technological Institute of Chemical and Food Industry, Wrodaw, Poland: Derivatographic Examinations of Poly(styrene-divinylbenzene)-type Cation Exchangers with Phosphorus-containing Functional Groups The thermal stability of organophosphorus cation exchangers obtained from styrene-divinylbenzene copolymers of Wofatit type was studied by means of T G - D T G - D T A techniques (in air or argon). Resins with gel and macroporous structure containing phosphinic or phosphonic acid functional groups, or both were examined. Relationships between the thermal characteristics, the kind of functional groups and the structure of the matrix were established. The activation energies of thermal degradation of the resin tested were calculated by the Horowitz-Metzger method. Comparative results for Wofatit commercial cation exchangers with -SO3H and - C O O H groups were also obtained. These proved to have higher thermal stability than the other phosphorus-containing cation exchangers. To be published in J. Therm. Anal.
S. Milesz and G. Lustyik, Isotope Laboratory, Kossuth Lajos University, and VILEG Laboratory, University Medical School of Debrecen, Debrecen, Hungary: Structure and Ion Exchange Properties of Crystalline Antimonic Acid Sorption properties, structure of crystalline antimonic acid and the mechanism of sorption were studied. For the measurements alkali metal ions and "static" labelling method were used. The particle size distribution curve of the sorbent was plotted by means of scanning electron micrographs of different enlargements. It shows that the major portion of the particles is of about 2 - 4 x 10 -5 m radius. Thus~ an expected fast sorption is characteristic of the system.
A Bilewicz, B. Barto~, H. Polkowska-Motrenko and J. Narbutt, Department of Radiochemistry and Department of Analytical Chemistry Institute of Nuclear Chemistry and Technology, Warsaw, Poland: New Composite Ion Exchanger--Hydrated Antimony Pentoxide in Phenolsulphonic Matrix--and its Application in Neutron Activation Analysis Crystalline antimony pentoxide (HAP), commonly used in neutron activation analysis for selective removal of sodium-24 ions from hydrochloric acid solutions of the irradiated samples, is not free from some substantial drawbacks; e.g., slow kinetics of the sorption process, irregular shape of the grains and low resistance of the material against hydrochloric acid even at high concentrations. In order to improve the properties of the sorbent, the powdered HAP was implanted into a matrix of a phenolsulphonic resin. The spherical beads of the composite sorbent obtained are characterized by good mechanical properties, high stability in hydrochloric acid solutions and improved kinetics of ion exchange. The distribution coefficient of Na + in 5 M HC1 for the composite sorbent containing 60% HAP ( K d = 2 × 103 cm3/g) is close to that for the pure crystalline HAP grains ( K d = 3 x 1 0 2 cm3/g). The HAP composite ion exchanger was used for the determination of Cu and Mn in biological materials. Accepted for publication in Anal. Chem.