Abstract
This chapter deals with the history of hydrotalcite and hydrotalcite-based
materials. A rare mineral known as hydrotalcite was found in Sweden sometimes in the
1840s. Magnesium aluminum hydroxycarbonate, Mg6Al2
(OH)16CO34H2O, is its
chemical name, and Taylor and Allmann independently determined its layered
structure. For a long time, hydrotalcite and other isomorphous minerals (such as
piroaurite, sjogrenite, and takovite) were the focus of most mineralogical studies.
However, beginning in the 1970s, it was discovered that these rare minerals, also
known as anionic clays, could be prepared quickly and affordably in a laboratory and
have a variety of intriguing chemical properties. The different arrangements of the
stacking of the layers, the ordering of the metal cations, as well as the arrangement of
anions and water molecules in the interlayer galleries, result in a variety of
stoichiometry in hydrotalcite, which are layered double hydroxides. Due to their unique
characteristics, including their enormous surface area, ion exchangeability, insolubility
in water, and most organic sorbents, among others, the compounds of the hydrotalcite
group demonstrate a wide variety of potential uses.