Selective binding of ions by polyelectrolyte gels. Volume change criterion

Journal Article · Mon Apr 01 04:00:00 EDT 1974 · J. Amer. Chem. Soc., v. 96, no. 7, pp. 2054-2058

DOI:https://doi.org/10.1021/ja00814a011· OSTI ID:4301160

Boyd, G E; Bunzl, K

The volume changes, DELTA V, which accompany the selective binding of ions in ion-exchange reactions at 25 deg C between aqueous electrolyte mixtures and polyelectrolyte gels were measured in an attempt to establish the range of applicability of the Katchalsky and the Rice- Harris theories. The DELTA V for the exchange of singly charged ions in lightly crosslinked polystyrene type strong-acid or strongbase ion-exchanger gels were small and positive or negative depending on the nature of the ions. Large, positive volume changes were observed with multiply charged cations. In general, DELTA V became more positive with increased gel crosslinking and with the strength of binding as measured by the decrease in the standard free energy, DELTA G deg , in the ion- exchauge reaction. Four types of ionbinding processes were distinguished: (a) field binding; (b) site binding via ion-pair formation; (c) structure-enforced binding; and (d) charge-transfer binding. Multiply charged cations (i.e. Ca/ sup 2+, Ba/sup 2+/, La/sup 3+/, Th/sup 4+) were selectively bound as ion pairs in all ge ls. Field binding could be inferred only for the selective uptake of singly charged cations in the lightly crosslinked gel. (auth)

• Research Organization: Oak Ridge National Lab., TN
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-029082
• OSTI ID: 4301160
• Journal Information: J. Amer. Chem. Soc., v. 96, no. 7, pp. 2054-2058, Journal Name: J. Amer. Chem. Soc., v. 96, no. 7, pp. 2054-2058; ISSN JACSA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*BARIUM-- ION EXCHANGE
*CALCIUM-- ION EXCHANGE
*CATIONS-- ION EXCHANGE
*GELS-- VOLUME
*LANTHANUM-- ION EXCHANGE
*THORIUM-- ION EXCHANGE
AQUEOUS SOLUTIONS
BARIUM COMPOUNDS
BINDING ENERGY
CALCIUM COMPOUNDS
FREE ENERGY
ION EXCHANGE MATERIALS
LANTHANUM COMPOUNDS
N40210* --Chemistry--Inorganic
Organic
& Physical Chemistry--Chemical & Physiochemical Properties
N40420 --Chemistry--Radiochemistry & Nuclear Chemistry--Properties of Radioactive Materials
THORIUM COMPOUNDS