Layered double hydroxides: Surface sorption, anionic exchange and phase segregation.

MATÍAS JOBBÁGY

Tsukuba, JAPAN

Workshop; Workshop on layered materials; 2008

National Institute for Materials Science

Layered double hydroxides (LDH), also known as anionic clays, are synthetic materials that exhibit fast anionic exchange properties, at ambient conditions. The control and prediction of anionic exchange properties is of great relevance in materials science. The intrinsic affinity of the anions involved in an exchange reaction are typically dictated by the charge to size ratio. Typically, those reactions are described in terms of ideal behavior. However, in certain conditions the structural differences between the anions triggers a phase segregation phenomena. In addition, certain specific interactions between the anchoring groups of the involved anions and the border sites of the LDH particles can superimpose to the exchange isotherm. The relative weight of each one of the aforementioned factors is discussed in light of several examples.