Organic/inorganic nanocomposites (NCs) are functional materials
consisting of immiscible organic and inorganic components,
and complex nanometer-scale structures can be fabricated therefrom.
As a typical example, polymer/clay NCs have been extensively
studied and successfully developed for many applications
[1]. In 2002, Haraguchi reported the creation of a novel ‘‘nanocomposite
hydrogel” with a unique organic–inorganic network structure
by extending the concept of NC to the field of soft hydrogel
materials [2]. The nanocomposite hydrogel (abbreviation: NC gel)
exhibited extraordinary mechanical, optical, swelling/deswelling
properties which could simultaneously overcome the limitations
of conventional chemically crosslinked hydrogels (abbreviation:
OR gels). The construction of NC gels was achieved, not by the mere
incorporation of clay nano-particles into a chemically crosslinked
network, but by allowing the clay platelets to act as multifunctional
crosslinkers in the formation of polymer/clay networks.
Due to their superior properties, NC gels have attracted much
attention and are believed to be a revolutionary type of hydrogel
[1]. This article reviews the fundamental and recent developments
in the field of NC gels.