Anisotropic networks

The formation, properties and applications of anisotropic, predominantly liquid-crystalline (LC), networks are described. These self-assembling systems exhibit macroscopic anisotropic (sometimes non-centrosymmetric) orientation in electric or magnetic fields, under strain or on orientation layers stabilised thermally and over time by cross-linking in thin films. The present review describes nematic (N), chiral nematic (N*), smectic (S-A, S-C*) and discotic elastomers and/or networks and gels, non-linear optical (NLO) films, linear photo-polymerised (LPP) orientation layers, reversible LC networks, etc. Many of these anisotropic networks exhibit piezoelectric, pyroelectric, ferroelectric and NLO properties. They are of potential interest for use in many electro-optic devices for optical communication and processing technologies.