Kinetics, equilibria and thermodynamics of ion exchange in substituted tobermorites

Michihiro Miyake, Sridhar Komarneni, Rustum Roy

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

The Al+Na and Al+K substituted tobermorites have been hydrothermally synthesized at 175°C under saturated steam pressure and their ion-exchange characteristics for K+ and Cs+ ions have been investigated from kinetics, equilibria and thermodynamics points of view. The initial exchange of Na+ in Al+Na substituted tobermorite with K+ and Cs+ ions was found to progress by diffusion of K+ and Cs+ ions. The activation energy for the Na → K exchange was evaluated to be smaller than that for Na → Cs exchange. The standard free energy changes for the cation exchange reactions were estimated at two total molarities of 1.0 × 10-3 and 3.0 × 10-3 mol/l which were found to be negative and the affinity of univalent cations for both Al+Na and Al+K substituted tobermorites at 25°C was found to follow the order: Na+ <K+ <Cs+. These basic studies suggest that the substituted tobermorites are selective for certain ions such as Cs+ and therefore they can be used in cation exchange separations.

Original languageEnglish
Pages (from-to)311-320
Number of pages10
JournalMaterials Research Bulletin
Volume24
Issue number3
DOIs
Publication statusPublished - 1989
Externally publishedYes

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Ion exchange
Thermodynamics
Ions
Cations
thermodynamics
Kinetics
kinetics
Positive ions
ions
cations
Steam
Free energy
Activation energy
steam
affinity
free energy
tobermorite
activation energy

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

Cite this

Kinetics, equilibria and thermodynamics of ion exchange in substituted tobermorites. / Miyake, Michihiro; Komarneni, Sridhar; Roy, Rustum.

In: Materials Research Bulletin, Vol. 24, No. 3, 1989, p. 311-320.

Research output: Contribution to journalArticle

Miyake, Michihiro ; Komarneni, Sridhar ; Roy, Rustum. / Kinetics, equilibria and thermodynamics of ion exchange in substituted tobermorites. In: Materials Research Bulletin. 1989 ; Vol. 24, No. 3. pp. 311-320.
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