Layered Double Hydroxides and the Environment: An Overview - Advanced Materials for Agriculture, Food and Environmental Safety - page 15

Since the catalytic behavior depends primarily on the chosen metals as
the catalytic centers [1], metal cations present in the brucite-like layers of
the LDHs play an important role for the catalytic properties of the i nal
product. Moreover, the anions present between the layers of the LDHs can
have an inl uence on the catalytic properties. h e anions present in the
LDHs can also have an ef ect on other properties such as the crystal size of
the catalysts.
1.6.2 AgriculturalApplications
Layered double hydroxides possess excellent potential as green carrier for
plant nutrients, pesticides and growth regulators and as active principle
in animal feeds. However, not much attention has gone into exploring the
full potentiality of LDHs. h ey are one of the idealized inorganic materi-
als for a wide range of agricultural i elds not only because their frame-
work can be composed of plant nutrients, but also because their structure
of ers charming features such as accommodation and controlled release of
various active anionic agro-substances, high buf ering capacity, high water
retention ability and acid neutralizing potential.
Komarneni et al. [94] suggested nitrate-LDH as a potential slow-release
fertilizer by synthesizing nitrate-LDH in ambient condition without any
considerable contamination of carbonate-LDH. More attention has been
given to pesticide formulation that consists mainly of various organic sol-
vents. Lakraimi et al. [95] prepared pesticide-LDH hybrid with 2,4- dichlo-
rophenoxyacetate, a broad leaf herbicide, by ion-exchange reaction with a
chloride form of ZnAl-LDH for slow release formulation. h e acid neu-
tralizing potential and high anion adsorption capacity of LDHs could be
explored for animal feeds as a complement to cationic clays, provided their
nontoxicity is ensured.
1.6.3 PharmaceuticalApplications
Pharmaceutical applications of LDHs mainly depend on the acid buf ering
ef ect and anion exchange property. LDH-derived antacid and antipeptic are
representative of their applications in pharmaceutics [96]. Powdered LDHs
have been demonstrated to be one important type of green carrier or host
for genes and drugs due to the excellent biocompatibility and nontoxicity
or low toxicity. MgAl-LDH is used as an important component of drugs, or
as nanocarrier for delivery of drugs and genes into cells [97, 98]. Wei et al.
[99] demonstrated that LDH was able to be used as an ef ective nanocar-
rier by greatly enhancing the thermal- and photo-stabilities for L-Dopa and