Microwaves-Mediated Preparation of Organoclays as Organic-/Bio-Inorganic Hybrid Materials

An innovative approach in the field of nanomaterials is to develop modern and mild synthetic protocols that enable controlled and integrated organization of specific functional organic and biological building blocks. In this context, research on the preparation of clay-based organic-inorganic hybrid materials, i.e. organoclays, has received considerable attention because these lamellar materials not only possess highly ordered structure in 2D, but also provide interesting chemical intercalation and surface properties. As a result entrapment and orientation of various functional guest molecules into layered inorganic solids, has been well exploited. At present there is a great deal of interest in the rational design of hybrid organic-/bio-inorganic composites on the nanometer to micrometer length scales. These hybrids encompass highly selective recognition properties associated with organic and biological species, combined with catalytic, optical, and electronic properties of the inorganic lamellar framework. This paper presents an overview of microwave application in different preparation steps of organophilic clays, their modification and their addition to polymeric matrices. Particular attention has been given to the microwave-mediated hydrothermal technique, as innovative and eco-friendly protocol for the intercalation of different kinds of organic hosts into the interlayer of clay minerals. The few pioneering complete microwave-mediated preparation procedures, exploiting advantages of dielectric heating in both the synthesis of the organic host molecule and the intercalation in the clay structure, have been also highlighted.