Temperature dependent AFM on ultrathin oriented films of FLC elastomers

Crosslinked ferroelectric liquid crystalline polymers are studied by atomic force microscopy. Polysiloxane copolymers have been synthesized with mesog enic and photo-crosslinkable side groups, the latter connected either direc tly to the backbone via a shea spacer, or as terminal group on a part of th e mesogens. These elastomers are prepared as thin freely suspended films in homeotropic orientation. The topography consists of plateaus separated by steps of characteristic height, corresponding to the surfaces and edges of smectic layers. From the temperature behavior as well as from the reaction to mechanical deformation, a model for the network architectures is propose d: In the first case ("intra-layer crosslinking"), a predominantly two dime nsional network is formed within the backbone layers separating the smectic layers, in the second case ("inter-layer crosslinking") a primarily three dimensional network is established which is dependent on the mesophase of c rosslinking.