Yi. Tarasevich et Vs. Rak, INVESTIGATION OF THE SELECTIVITY OF MONTMORILLONITE FOR CATIONS OF THE ALKALI AND ALKALINE-EARTH METALS IN THE PRESENCE OF NONIONIC SURFACTANTS, Colloid journal of the Russian Academy of Sciences, 55(5), 1993, pp. 754-759
Nonionic surfactants penetrate into the interlayer interstices of mont
morillonite, forming mono- or bilayer inclusion compounds, depending o
n the nature of the exchange cation, with a parallel orientation of th
e molecules relative to the basalt faces of the crystals, whereas in t
he case of Na and K samples, there is also an inclined arrangement of
molecules relative to the aluminosilicate layers of the mineral. The i
ntroduction of a nonionic surfactant increases the selectivity of mont
morillonite to large cations of the alkali and alkaline earth metals b
y a factor of 2 to 1. 3. This is explained by the formation of complex
cations with oxygen, primarily eight-membered rings of the oxyethyl p
ortion of the nonionic surfactant molecule.