Intercalation of malachite green ([C6H5C(C6H4N(CH3)2)2]Cl) in layered γ-zirconium phosphate. Effect of cationic surfactants

Abstract

The intercalation of malachite green (MG) in γ-zirconium phosphate (γ-ZrP) and one of its cationic surfactant forms (γ-ZrP/SUR⁺) has been investigated by the batch method and followed by X-ray diffractometry. X-Ray diffraction patterns showed that an impure phase (1.18 and 1.96 nm) was obtained with γ-ZrP while a pure one (2.47 nm) with γ-ZrP/SUR⁺ at a dye loading of 14% and 18%, respectively. In both cases, computer models and calculations based on the dye dimensions and the structure of the host showed that the maximum ion-exchange capacity is ca. 12–16%, which reflects the very high capacity by which γ-ZrP and γ-ZrP/SUR⁺ are characterized in the uptake of MG. The difference in the dye loading between the corresponding derivatives of pristine γ-ZrP and γ-ZrP/SUR⁺ is attributed to the difference in interlayer distances and the variable cross-section of the dye depending on its orientation and/or conformation within the interlayer region.