Gibbs-Donnan Equilibria in Ion Exchange Resin Systems

Gregor, Harry P.

doi:10.1021/ja01146a042

Cited by 224 publications

(79 citation statements)

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“…This is not accounted for by the poreswelling model, which only considers the osmotic properties of the internal solution. A possible theoretical interpretation may be available from the thermodynamics describing ion exchange equilibria within polyelectrolyte resins (Gregor 1951;Glueckauf 1952). Such theories have been used to explain the selectivity of resins for different ions, where it is proposed that ions of identical charge are preferred according to the inverse of their partial molar volumes.…”

Section: Gel Swelling Equilibriamentioning

confidence: 99%

“…A further Eq. 11 has been described in the literature, which relates the equilibrium position of an ionexchange reaction to the value of a new thermodynamic quantity, which can be called the gel-pressure (Gregor 1951). Here m CNa , and m CH are the respective molar volumes taken up by the exchanging ions in the unit cell, which can be determined from the density differences between cellulose II and either Nacellulose VI or Na-cellulose-I.…”

Section: Gel Swelling Equilibriamentioning

confidence: 99%

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Interpretation of relaxation and swelling phenomena in lyocell regenerated cellulosic fibres and textiles associated with the uptake of solutions of sodium hydroxide

2007

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The uptake of solutions of sodium hydroxide by lyocell fibre results in a phenomenon in textiles described as swelling-shrinkage. The response of woven fabrics in a tensile stress-relaxation experiment shows two time-dependent processes, corresponding to different mechanisms of pressure development. Rapid diffusion has been assigned to osmotic swelling through the interconnected pore structure of the fibre (D = 6-15 9 10 @12 m 2 /s), which is influenced by the extent of ionization of hydroxyl groups at the pore surfaces. A ratio for the cellulose and water dissociation constants (K cell /K w ) of 70 provides best agreement with experimental data. A second slower diffusion process (D = 2-10 9 10 @14 m 2 /s) is assigned to transport through the cellulose polymer structure, associated with the Na-cellulose transition. This can be modeled assuming an ion-exchange equilibrium, where the cellulose gel converts reversibly between compact hydrogen and expanded sodium forms, with K = 1.04 9 10 14 , in favour of the hydrogen form. The model successfully predicts the concentration dependence of the transition and the movement to higher concentration with external constraint. The slow diffusion process only becomes apparent at high alkali concentrations, as the pores in the fibre collapse due to the expansion of the gel. Continued gel-diffusion is only possible through the polymer phase, which then dominates over fast pore-diffusion.

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Section: Gel Swelling Equilibriamentioning

confidence: 99%

Section: Gel Swelling Equilibriamentioning

confidence: 99%

Interpretation of relaxation and swelling phenomena in lyocell regenerated cellulosic fibres and textiles associated with the uptake of solutions of sodium hydroxide

2007

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“…The phenomenon is reversible and a consequence of the strongly hydrophilic nature of the groups that give the resin its ion exchange properties. The degree to which swelling occurs is controlled by two opposing forces namely the osmotic pressure in the resin (due to differences in concentration of the solution in and out of the resin) and the strain to which the elastic polymeric network is submitted (219). Therefore the amount of swelling depends on:…”

Section: Swellingmentioning

confidence: 99%

Cation-Exchange Techniques in Radiochemistry.

Massart¹

1971

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“…Further, the relative partial affinity coefficient is defined by k.=k..(~~), (4) so that Eq. ( 3) reduces to log K= -0.4343+ fa' log ka·dXn.…”

Section: 203rtmentioning

confidence: 99%

Studies on Cation Exchange Equilibria for the Uranyl-Hydrogen System

Hagiwara

Ochiai

1968

J. Nucl. Sci. Technol.

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Selectivity coefficients of the uranyl-hydrogen ion exchange system have been determined in a series of sultonated polystyrene type cation exchange resins in three different degrees of crosslinkage at four different temperatures. The standard free energies of exchange LJG 0 and the h£ats of exchange L1H were also estimated from the data of selectivity coefficients determined on the same resins.In general, the selectivity coefficient increased with both crosslinkage and temperature, and decreased with increasing proportion of uranyl in the resin phase. The study was further extended to the exchange system of uranyl-ammonium in order to ascertain the validity of the magnitudes of selectivity coefficients obtained for the uranyl-hydrogen system. Good results were obtained on the exchange equilibria.

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Gibbs-Donnan Equilibria in Ion Exchange Resin Systems

Cited by 224 publications

References 0 publications

Interpretation of relaxation and swelling phenomena in lyocell regenerated cellulosic fibres and textiles associated with the uptake of solutions of sodium hydroxide

Interpretation of relaxation and swelling phenomena in lyocell regenerated cellulosic fibres and textiles associated with the uptake of solutions of sodium hydroxide

Cation-Exchange Techniques in Radiochemistry.

Studies on Cation Exchange Equilibria for the Uranyl-Hydrogen System

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