Temperature Dependent AFM on Ferroelectric Liquid Crystalline Polymer and Elastomer Films

Abstract

Ferroelectric liquid crystalline (LC) polymers are studied by temperature dependent atomic force microscopy (AFM). The samples, thin films of homeotropic orientation prepared as freestanding films, are imaged in four mesophases. Two types of molecular networks are compared: A two-dimensional cross-linking of backbone layers (“intralayer” cross-linking) and a cross-linking via the mesogens (“interlayer” cross-linking). While non-cross-linked films reorient during annealing, in cross-linked films the layer structure remains even in the isotropic phase. The surface morphology and the dependence of smectic layer thickness (tilt angle) on temperature reflect the molecular structure of the network.