Clay–polymer materials are important nano–micro composites with enormous possibilities for industrial scale up. Demand is rising for these materials on account of their excellent characteristics, including toughness, stiffness, dimensional stability, thermal resistance, chemical resistance, enhanced barrier properties and flexibility at high temperatures, and is expected to boost growth over the coming years. Nanoclay is a key factor in improving the material properties of common plastics such as polyolefins, engineering polymers and rubbers. Loading polymers with clay particles essentially increases the material’s strength as well as the plasticity and elongation for elastomers and rubbers; however, only recently have such composites been prepared with control of the material’s organization at the nanoscale. The design of organized clay–polymeric composites demands well defined clay nanoparticles. New methods of clay purification and techniques in surface modification have been developed to produce functional polymer–clay nanocomposites. The effectiveness of nanoclays in polymeric materials depends not only on the clay composition but also on the clay’s shape and size. Clay nanoparticles have been prepared as sheets a hundred nanometers wide (such as kaolin, montmorillonite, bentonite and rectorite) or elongated one to two micrometer tubular and fibrous clays such as halloysite, imogolite and sepiolite.

Clay nanotubes may be loaded with anticorrosion, antioxidant, flame-retardant or antibacterial agents, and other chemically active compounds. Controlled release of chemical agents from nanotubes embedded in a polymeric matrix provides new long lasting properties for material composites, often called “smart” composites, with self-healing properties. The release time of chemical agents may be adjusted for weeks, months and years providing sustained functionality. Fibrous clays are particularly interesting for applications with biopolymers and other “green” polymers. These long needle-like structures imbue composites with greatly enhanced mechanical properties and can be functionalized similarly to tubular structures. Fibrous and tubular clays, in particular, are attracting particular interest in compounding with drugs, proteins and nucleic acids. Traditional applications of clay in the cosmetics industry can be extended to more efficient pharmacological uses, including controllable drug release and intracellular delivery of polymer–nanoclay drug formulations.

This book fills a gap in the description of nanoclay research by analyzing clay structures at the nano, micro and macro scales rather than the earlier approaches which were primarily concerned with the bulk properties of the clay. Clay is a natural compound and in most cases it is a biocompatible material, which means that clay materials pose little to no risk to the environment even at mass industrial applications. This 15-chapter book combines the efforts of US, Chinese and European authors and emphasizes eco-friendly “green” nanomaterials with sustained functionality based on natural clay composites. Special attention is devoted to nanosafety aspects which provide an optimistic prognosis for the mass application of nanoclay in household products, which has a historical background starting from porcelain and pottery production traditions.

Yuri Lvov, Baochun Guo and Rawil F. Fakhrullin