Preparation and characterization of ionic liquid intercalation compounds into layered zirconium phosphates

In this work, immobilizing a series of ionic liquids (ILs) 1-alkyl-3-methylimidazolium chloride [Cnmim]Cl (n = 2, 4, 6, 8) on the layered zirconium phosphates were investigated. [C4mim]Cl was used to explore in detail the factors affecting intercalation. By comparing several starting materials including a-zirconium phosphate (a-ZrP), c-zirconium phosphate (c-ZrP) and the corresponding alkylamine preintercalated composites, it was found that the a-ZrP 2BA (i.e., preintercalated BA were arranged in a bilayer mode at the galleries of a-ZrP) was a suitable host for intercalating ILs. Intercalation was verified with X-ray diffraction (XRD), Raman, UV–Vis and other instrumental approaches. pH effect on immobilization was investigated. Other ionic liquids including [Cnmim]Cl (n = 2, 6, 8) intercalation compounds were prepared. Based on XRD data, the interlayer distances of the studied intercalation compounds were similar, suggesting that the ionic liquids were arranged in an approximately planar manner, as confirmed by molecular modeling.