CREATION AND STRUCTURAL COMPARISON OF ULTRATHIN FILM ASSEMBLIES - TRANSFERRED FREELY SUSPENDED FILMS AND LANGMUIR-BLODGETT-FILMS OF LIQUID-CRYSTALS

The transfer of freely suspended (FS) liquid-crystalline (LC) films onto solid supports offers the possibility of creating smectic multilayer films that, depending on the material and the phase state, can in principle be monolayer (head-to-tail) or bilayer (head-to-head and tail-to-tail) structures. The use of amphiphilic liquid-crystalline compounds enables the direct comparison of transferred freely suspended (TFS) films with Langmuir-Blodgett (LB) films of the same material. In the case of ethyl-4'-n-octyloxybiphenyl-4-carboxylate (1) the LB films are originally deposited as bilayers that rearrange to monolayer structure within hours. The TFS films of 1 exhibit a monolayer structure with the same layer spacing as the rearranged LB film (24 angstrom). However, the thermal stability of the TFS films is superior to that of LB films, which start to melt at 80-degrees-C. The TFS films melt at 110-degrees-C, which is also the clearing point of the bulk material. An additional advantage of the TFS films is that they can be obtained as monodomains.