INVESTIGATION OF THE SELECTIVITY OF MONTMORILLONITE FOR CATIONS OF THE ALKALI AND ALKALINE-EARTH METALS IN THE PRESENCE OF NONIONIC SURFACTANTS

Nonionic surfactants penetrate into the interlayer interstices of montmorillonite, forming mono- or bilayer inclusion compounds, depending on the nature of the exchange cation, with a parallel orientation of the molecules relative to the basalt faces of the crystals, whereas in the case of Na and K samples, there is also an inclined arrangement of molecules relative to the aluminosilicate layers of the mineral. The introduction of a nonionic surfactant increases the selectivity of montmorillonite to large cations of the alkali and alkaline earth metals by 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 portion of the nonionic surfactant molecule.