Porenstrukturuntersuchungen von Kunstharzaustauschern durch Austauschadsorption großer organischer Farbstoffe

Gärtner, Kim Angeles; Grieβbach, R.; Anton, Ernst

doi:10.1007/bf01520668

Cited by 12 publications

(7 citation statements)

References 5 publications

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“… Consistent with the pore size explanation is that larger ions were found to exchange more slowly . Moreover, increases in the degree of cross-linking in polymers prepared with as much as 16 mol % cross-linker lowered the ion exchange capacity for larger ions. , Reports in the ISE literature that suggest an effect of ion size exclusion on measured EMF responses are few, though. , It was suggested that asymmetric cellulose acetate membranes hindered the access of salicylate ions into carbonate-selective membranes because of their large ion size, resulting in slow responses to salicylate and high selectivities . A similar explanation was also given for plasticized PVC membranes doped with an ionophore attached to a non-cross-linked poly(4-vinylpyridine- co -styrene) backbone .…”

Section: Resultsmentioning

confidence: 88%

“…Indeed, studies performed with a view to ion separations showed that hydrophilic, high capacity, polymeric ion exchangers may exhibit an ion exchange capacity that is smaller for large than for small ions. This has been explained by a distribution of pore sizes within these ion exchangers, which makes some ion exchange sites inaccessible to large counterions. , For example, the anion exchanger De-Acidite E was reported to have an ion exchange capacity of 1.22 mequiv/g for the comparatively small sulfate but only 0.36 mequiv/g for the much larger carmoisine (see Figure ). Consistent with the pore size explanation is that larger ions were found to exchange more slowly .…”

Section: Resultsmentioning

confidence: 99%

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Donnan Failure of Ion-Selective Electrodes with Hydrophilic High-Capacity Ion-Exchanger Membranes

et al. 2015

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Hydrophilic ion-exchanger membranes with a high ion-exchange capacity not only find numerous applications in ion separations, but also have interesting properties when used as sensing membranes of ion-selective electrodes (ISEs). As pointed out in the literature, the hydrophilic nature of these membranes may reduce biofouling of ISE sensing membranes as caused by electrically neutral, hydrophobic interferents. This work shows that hydrophilic high-capacity ion-exchanger membranes are more resistant to Donnan failure (i.e., the limitation of the upper detection limit by co-ion transfer into the sensing membrane) than both hydrophobic ionophore-doped and hydrophobic ionophore-free ion-exchanger membranes. Nernstian responses of hydrophilic anion-exchanger membranes were found for anions as large as 2.0 nm, in spite of the cross-linked nature of the anion exchanger that was used. This shows that the high resistance of hydrophilic anion-exchangers to Donnan failure caused by cations such as tetrabutylammonium is not the result of size exclusion. For typical ions, the hydrophilicity of the anion exchanger does not play a decisive factor either. Instead, the excellent resistance to Donnan failure exhibited by hydrophilic ion exchange membranes is primarily caused by the high activity of exchangeable ions in the ion exchanger phase, which disfavors partitioning of ions of opposite charge (along with target ions) from samples into these sensing membranes. The absence of Donnan failure caused by hydrophobic co-ions may be of substantial benefit for measurements in biological samples.

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Section: Resultsmentioning

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Donnan Failure of Ion-Selective Electrodes with Hydrophilic High-Capacity Ion-Exchanger Membranes

et al. 2015

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“…The HAS ions are retained on cation exchange resins containing 8% of divinylbenzene (DVB) (Wada and Wada 1980). The sizes of the HAS ions are expected to be smaller than approximately 1.7 nm because the maximum pore size of that type of cation exchange resin is estimated to be 1.77 nm (Gärtner et al . 1961).…”

Section: Resultsmentioning

confidence: 99%

Reactivity with phosphate and phytotoxicity of hydroxyaluminosilicate ions synthesized by instantaneous mixing of aluminum chloride and sodium orthosilicate solutions

Nakanishi

Wada

2007

Soil Science and Plant Nutrition

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Hydroxyaluminosilicate ions are important as precursors of imogolite in synthetic systems and as less toxic aluminum-bearing species in natural aquatic systems. Despite their importance, their structures and properties have not been fully elucidated. We prepared a solution of hydroxyaluminosilicate ions by instantaneous mixing of solutions of sodium orthosilicate and aluminum chloride and carried out phosphatebinding experiments and phytotoxicity testing. To avoid possible alteration by drying, phosphate binding was measured in hydroxyaluminosilicate solutions contained in dialysis bags. The amount of phosphate bound to hydroxyaluminosilicate ions linearly increased as the equilibrium phosphate concentration increased up to 0.7 mmol L -1 . The amounts of bound phosphate were lower than those of imogolite and allophanes at relatively low phosphate concentrations; however, phosphate binding by hydroxyaluminosilicate ions surpassed binding by allophane and imogolite at equilibrium phosphate concentrations > 0.4 mmol L , at which concentration the hindrance by hydroxyaluminum and aluminum ions was 80 -85%. These results suggest that hydroxyaluminosilicate ions have very low biological activity in natural waters.

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“…(6) and (7) Reaction path B cornprises the following steps: B1 Preparation of the arninophenyl derivative of cellulose:…”

Section: New Synthesis Of Cellulose Exchangersmentioning

confidence: 99%

New ion exchangers, preparation, properties and application

Lieser¹

1979

Pure and Applied Chemistry

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Summary -Properties of various polystyrene/divinyl benzene resins are discussed. Rigidity and porosity are investigated by radiochemical methods, also the kinetic behaviour of macromolecular resins and those of normal porosity. Kinetic properties of superficially and of thoroughly sulfonated resins are compared. The synthesis of resins with tetraphenyl borate as anchor group is described.Cellulose as a natural macromolecular matrix can also be used for synthesis of ionexchangers. New ways of synthesis are described. Capacity and kinetic properties are determined and discussed. Comparison of distribution coefficients serves as a measure of selectivity. Selectivity of the new ion exchangers is demonstrated. Examples of application are described.

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Porenstrukturuntersuchungen von Kunstharzaustauschern durch Austauschadsorption großer organischer Farbstoffe

Cited by 12 publications

References 5 publications

Donnan Failure of Ion-Selective Electrodes with Hydrophilic High-Capacity Ion-Exchanger Membranes

Donnan Failure of Ion-Selective Electrodes with Hydrophilic High-Capacity Ion-Exchanger Membranes

Reactivity with phosphate and phytotoxicity of hydroxyaluminosilicate ions synthesized by instantaneous mixing of aluminum chloride and sodium orthosilicate solutions

New ion exchangers, preparation, properties and application

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