Using polymers to direct the self-assembly of complex liquid crystalline phases

While the anchoring of simple liquid crystalline phases, such as nematics, is well-understood, alignment of complex liquid crystals such as blue-phases and discotics is more challenging. We present here two methods to align complex liquid crystalline phases, namely chemo and grapho-epitaxy. These techniques involve making chemical (chemoepitaxy) and topographical (grapho-epitaxy) patterns using nanolithography. Chemo and grapho-epitaxy are well established techniques in the field of block copolymers. We present here extensions of these techniques for assembly of liquid crystalline phases. We demonstrate how directed self-assembly of blue-phase and discotic liquid crystals can be used to prepare polymeric photonic single crystals and biaxially textured crystals of organic semiconductors, respectively.