Reactivity towards electron of azide ion in metal–metal ion-exchange reactions

1965 ◽  
Vol 0 (18) ◽  
pp. 429-430
Author(s):  
A. A. Moussa ◽  
M. M. Abou Romiah ◽  
M. A. Razik
Keyword(s):  
Ion Exchange ◽  
Metal Ion ◽  
Exchange Reactions ◽  
Azide Ion ◽  
Metal Metal ◽  
Metal Ion Exchange

Alkali metal ion exchange selectivity of Al-substituted tobermorite

1989 ◽  
Vol 4 (3) ◽  
pp. 698-703 ◽  
Author(s):  
Masamichi Tsuji ◽  
Sridhar Komarneni
Keyword(s):  
Ion Exchange ◽  
Alkali Metal ◽  
Cation Exchange ◽  
Separation Factor ◽  
Metal Ion ◽  
Infinite Dilution ◽  
Exchange Reactions ◽  
Alkali Metal Ion ◽  
Metal Ion Exchange ◽  
Exchange Selectivity

Alkali metal ion exchange isotherms at a total ionic strength of 0.001 M were determined at 25 °C on a 1.13 nm anomalous [Al3+ + Na+]-substituted tobermorite with the formula, Ca5Na0.75Al0.9Si5.1O16(OH)2 · 6.03H2O. The Kielland plots of Na+/K+, Na+/Rb+, and Na+/Cs+ exchange reactions showed straight lines. The slopes were steeper for Cs+ and Rb+ exchange reactions, as compared to K+ exchange. The cation-exchange selectivity for alkali metals was found to increase as follows: Cs+>Rb+>K+>Na+. A new evaluation method of the separation factor (αMN/KMd/KNd,Kd: distribution coefficient) for a combination of two cations at infinite dilution was proposed in terms of the selectivity coefficient (KMNa) which can be easily determined from the Kielland plot. An extremely large separation factor for Cs (αCsNa = 112) was found at infinite dilution. These basic studies of cation exchange selectivity are of relevance in cation separation and purification and nuclear waste disposal.

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