Preparation of a new stable hybrid material by chloride-2,4-dichlorophenoxyacetate ion exchange into the zinc-aluminium-chloride layered double hydroxide

A new hybrid material with the composition [Zn1.9Al(OH)(5.8)][Cl2C6H3OCH2CO2. 2.83H(2)O] has been synthesised via ion exchange of chloride by ions of a molecule belonging to the pesticide family, 2,4-dichlorophenoxyacetate (2,4D). The ion exchange in the zinc-aluminium-chloride layered double hydroxide, [Zn-Al-Cl], was investigated by X-ray diffraction and infrared spectroscopy. The effects of the anion concentration in solution, the 2,4D/[Zn-Al-Cl] molar ratio, the ageing time and the temperature on the ion exchange were studied. The best sample, in terms of crystallinity and extent of ion exchange, was obtained at 100 degrees C in a 0.004 M 2,4D solution in which the 2,4D/[Zn-Al-Cl] molar ratio was equal to 11, with 24 h of stirring time. This hybrid material was further characterised by chemical analyses and its thermal behaviour was also studied.