Layered double hydroxides: fundamentals to applications

Layered double hydroxides are two dimensional layered nanomaterials, belong to anionic clay family, whose main advantage is that it can alone; hybrid form with other superior nanomaterials, its intercalation with functional materials and its exfoliation in polymer matrices can lead to world wide applications. In the introduction part, general awareness about layered double hydroxides, layered double hydroxide nanocomposites, layered double hydroxide based polymer nanocomposites are highlighted. As the primary step of layered double hydroxides based research is the synthesis of the layered double hydroxides, state of the art of synthesis of layered double hydroxides have been illustrated with some examples. The different pathways for the organic modification of LDHs are discussed, which open up new avenues to the fabrication of hierarchical layered double hydroxides based hybrid nanostructures with potential applications. The very important characterization techniques generally used to confirm the formation of LDH crystals and their modification are XRD, FTIR, SEM, TEM and AFM and are illustrated with suitable examples taken from previously reported research works. The broad spectrum applications of layered double hydroxides, modified layered double hydroxides, layered double hydroxide nanocomposites with other smart nanomaterials such as carbon nanotube, graphene, graphdiyne etc have been illustrated by taking suitable examples from the literature. Along this perspective, we have attempted to introduce the layered double hydroxide based polymer nanocomposites, their fabrication methods and their wide spread applications.