Journal ArticleDOI
Ion Exchange in Felspathoids as a Solid-State Reaction
Richard M. Barrer,J. D. Falconer +1 more
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In this article, a quantitative analysis of ion-exchange diffusion and equilibria in the felspathoids, basic cancrinite, basic sodalite, and K and Rb analcite is presented.Abstract:
A quantitative investigation has been made of ion-exchange diffusion and equilibria in the felspathoids, basic cancrinite (M$\_{2}$O.Al$\_{2}$O$\_{2}$.2$\cdot $4SiO$\_{2}$.0$\cdot $6 M OH.xH$\_{2}$O), basic sodalite (M$\_{2}$O.Al$\_{2}$O$\_{3}$.2$\cdot $5SiO$\_{2}$.0$\cdot $34 MOH.xH$\_{2}$O) and K and Rb analcite (M$\_{2}$O.Al$\_{2}$O$\_{3}$.4SiO$\_{2}$). The isotherm contours were of three kinds: an 'ideal' form obeying the mass action law K = (B$\_{c}$A$\_{s}$/A$\_{c}$B$\_{s}$) (Na-Li, Na-K, Li-K and Na-Ag in basic sodalite); a sigmoid form obeying the equation log$\_{10}$ K = log$\_{10}$ (B$\_{c}$A$\_{s}$/A$\_{c}$B$\_{s}$) + C(1-2B$\_{c}$) where the constant C takes a negative value (Na-Li in basic cancrinite); and a form exhibiting hysteresis (Na-Ag and Li-Ag in basic cancrinite and K-Rb in analcite). The hysteresis was shown to be due to limited mutual solid solubility of the end-members of the exchange and to an associated difficulty in nucleating crystallites of one growing phase on or in a matrix of the other. This effect is most strikingly found in the Rb-K exchange in analcite, for which various scanning loops were traversed. A quantitative approach to the theory of the above types of exchange isotherm has been given, and applied to the present and to earlier results obtained with crystalline exchangers. This gives a possible theoretical basis of the equation log$\_{10}$ K = log$\_{10}$ (B$\_{c}$A$\_{s}$/A$\_{c}$B$\_{s}$) + C(1-2B$\_{c}$) and for Kielland's equation log$\_{10}$ f$\_{Ac}$ = CB$_{c}^{2}$. Examination of selectivity coefficients shows that the crystalline exchangers may possess very high selectivities towards one alkali metal ion as against another or for heavy metal ions such as Ag or T1. These selectivities may change radically as one crystal is substituted for another. Ion sieve effects, partial or complete, were observed and can bring about a Donnan membrane hydrolysis of salts even of strong acids or bases, such as CsCl. Comparison has been made of the exchange diffusion coefficients evaluated in these laboratories for several kinds of crystal. A feature of exchanges where the temperature variable has been studied is the normally small temperature coefficient of the exchange equilibria and so a small value of the heat of exchange. A model has been proposed which regards the reactions as an interchange of ions between two inert dielectrics. This interpretation provides a simple explanation of the observed behaviour.read more
Citations
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The sodalite group of minerals
TL;DR: In this article, the results of a study of the chemical composition, cell parameters, density and refractive index of two sodalites and twenty five members of the nosean-hauyne solid solution series are given.
Journal ArticleDOI
Membrane macromolecules and nerve excitability: a physico‐chemical interpretation of excitation in squid giant axons
Ichiji Tasaki,Irwin Singer +1 more
Journal ArticleDOI
The sorption of silver by poorly crystallized manganese oxides
TL;DR: In this article, the sorption of poorly crystallized manganese oxides was studied using synthesized samples of three members of the manganous manganite (birnessite) group, of different chemical composition and crystallinity, and a poorly organized γ-MnO2.
Journal ArticleDOI
[NH3CH3]4[In4SbS9SH]: a novel methylamine-directed indium thioantimonate with Rb+ ion-exchange property
TL;DR: In this article, the protonated methylamine was successfully used to direct the formation of one novel indium thioantimonate compound, namely, [NH3CH3]4[In4SbS9SH] (1).
Journal ArticleDOI
Ion exchange on inorganic sorbents
TL;DR: In this paper, the principal features of the thermodynamics and kinetics of ion exchange processes in inorganic ion exchangers are discussed and the literature data on the ion exchange properties of oxide systems, globular hydrates, and salts of polyvalent cations are surveyed.
References
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Journal ArticleDOI
Activities of the Components in Ion Exchangers.
Journal ArticleDOI
386. Ion-exchange in crystals of analcite and leucite
R. M. Barrer,L. Hinds +1 more
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