Freely‐Suspended and Transferred Freely‐Suspended Films of Polymeric Liquid Crystals

Publisher Website
Google Scholar
Abstract
Freely‐suspended (FS) liquid‐crystal (LC) films of a polymethylsiloxane homo‐ and a copolymer with different mesogenic side groups have been prepared and investigated. For both substances the preparation of the films succeeded only in the isotropic phase but the higher ordered phases were reached after cooling. The films of the homopolymer have only been obtained with thicknesses estimated to be in the pm‐range and with an unusual “Book‐Shelf” orientation of the smectic layers. In contrast, the films of the copolymer were thinner and showed a homeotropic orientation of the mesogens in the smectic A phase. Interestingly, this material exhibited a different layer spacing in film and bulk, although no differences in the phase transition temperatures could be detected within experimental error. FS‐films of the homopolymer have been transferred to solid supports. Both the FS and the transferred freely‐suspended (TFS) films of this material were particularly stable as compared to films of low molecular weight compounds.