| 초록 |
A rod-coil block copolymer film comprised of a set of periodic splay-bend Nel-wall defect patterns was used as a template to pattern two liquid crystals (LC). LC cells were then constructed using the dry block copolymer film as the substrate and a glass plate as the superstrate. The nematic LC 5CB exhibited a replica texture of the defect pattern for thin LC cells. In thicker LC cells, regions of uniform nematic 5CB LC alignment and a coarsely spaced grating pattern coexisted. The LC, 4,4’-diheptylazoxybenzene(D7AOB) exhibited planar anchoring and the coarse grating pattern in its nematic state, while in the smectic state, uniform homeotropic alignment occurred over the entire surface of the sample. Due to high values of the twist and bend elastic constants in the smectic phase of D7AOB, switching between the coarse grating pattern and the uniform homeotropic pattern occurred at the nematic-smectic A transition temperature of D7AOB. |
