Cover Picture: Bistable Nematic Liquid Crystals with Self‐Assembled Fibers (Adv. Mater. 6/2005)

The cover shows a recording process using nematic liquid crystal alignment. On p. 692, Kato and co‐workers report that reversibly bistable states have been achieved for nematic liquid crystals incorporating a small amount of self‐assembled fibers. Homeotropic monodomains and non‐aligned multidomains can be fixed and switched by thermal treatment in electric fields. The technique is applied to the formation of rewritable light scattering patterns, as shown on the cover.     

Self‐Assembled Photonic Structures

Photonic crystals have proven their potential and are nowadays a familiar concept. They have been approached from many scientific and technological flanks. Among the many techniques devised to implement this technology self‐assembly has always been one of great popularity surely due to its ease of access and the richness of results offered. Self‐assembly is also probably the approach entailing more materials aspects owing to the fact that they lend themselves to be fabricated by a great many, very different methods on a vast variety of materials and to multiple purposes. To these well‐known material systems a new sibling has been born (photonic glass) expanding the paradigm of optical materials inspired by solid state physics crystal concept. It is expected that they may become an important player in the near future not only because they complement the properties of photonic crystals but because they entice the researchers’ curiosity. In this review a panorama is presented of the state of the art in this field with the view to serve a broad community concerned with materials aspects of photonic structures and more so those interested in self‐assembly.     

Supramolecular Materials via Block Copolymer Self‐Assembly

This review discusses the potential of block copolymer type macromolecular building blocks for the preparation of self‐assembled materials. Three different classes of block copolymer type architectures will be distinguished: (i) coil–coil diblock copolymers, (ii) rod–coil diblock copolymers, and (iii) rod–coil diblock oligomers. The basic principles that underlie the self‐assembly of each of these different building blocks will be discussed. These theoretical considerations are complemented with examples from recent literature that illustrate the potential of the different types of block copolymers to prepare (functional) supramolecular materials. Finally, several strategies will be presented that could allow the preparation of stimuli‐sensitive self‐assembled materials, i.e., materials whose properties can be reversibly manipulated under the action of appropriate external stimuli.