Lyotropic liquid crystals
In mixtures of soap and water, the special properties of soap molecules cause them to form clusters—and clusters of clusters—in a variety of interesting geometrical shapes. Some of these aggregates are liquid crystals, known as lyotropic, which are quite different from thermotropic liquid crystals, the focus of most of the work described in this issue of PHYSICS TODAY. Lyotropic liquid crystals are now receiving a great deal of scientific and technological attention because of the way they reflect the unique properties of their constituent molecules.