Adsorption of Safranine by Na+, Ni2+ and Fe3+ Montmorillonites
- 1 February 1977
- journal article
- Published by Cambridge University Press (CUP) in Clays and Clay Minerals
- Vol. 25 (1) , 19-25
- https://doi.org/10.1346/ccmn.1977.0250104
Abstract
The adsorption of the cationic oxidized safranine S+ by a Na+, Ni2+ and Fe3+ montmorillonite has been studied with X-ray powder diffraction, u.v., visible and i.r. spectroscopy. In solution S+ may be protonated: S+, SH2+ and SH23+ have characteristic spectra in the 500–600 nm region where the clay structure does not absorb. In the Na+ as well as in the Ni2+ and Fe3+ clays, the adsorption of S+ is a cation exchange process accompanied by the protonation of the adsorbed dye such as variable concentrations of M+ (Na+, Ni2+ or Fe3+), S+ and SH2+ are simultaneously present. Protonation activity decreases from Fe3+ to Ni2+ and Na+, being the protonation site the amine group as shown by i.r. In the interlamellar space it seems that a SH2+.. S+ association exists that could be described as a sandwich structure 6.5 Å thick.This publication has 5 references indexed in Scilit:
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