Additionally, a lot of different inorganic anions such as CO3

Layered double hydroxides (LDH), commonly termed as metal-metal-hydroxysalts and anionic clay minerals, are a group of natural and synthetic materials containing different chemical and structural alternating layers. Negative charged interlayers with reversibly exchangeable anions, additional cations and water molecules occur alternating to the positive charged brucite-like mainlayers (Bish 1980). Furthermore, additional cations and organic molecules can be fixed reversibly within the interlayer. One of the most important subgroup of the LDH represent the minerals of the hydrotalcite-group. The hydrotalcites are characterized by the ability of permanent interlayer-anion-exchange, which is recently used by industry (building-materials, catalyst) and pharmacy. The simplified chemical structure of LDH is [(Me(II)1-xMe(III)x(OH)2]x+[xA*nH2O]x-, with Me as metal cation and A as exchangeable anion. According to the widespread diversity of Me, a large number of LDHs have been synthesized with divalen