Bent-core liquid crystal molecules in confined geometries


The aggregation of individual molecules into a final desired structure via self-assembly is one of the most exciting inter- disciplinary research areas in condensed matter physics. Since self-assembly only gives rise to thermodynamically stable structures, techniques based on self-assembly tend to produce structures that are relatively defect-free and self-healing. Liquid crystal materials, notable for their ability to self-organize, represent an extremely versatile class of self-assembling materials with great potential in applications like optoelectronics, the study of biological membranes, and in the creation of nanopatterning templates. Here we investigate a new class of LC structures exhibited by bent-core smectics that form a variety of novel morphologies over large areas when confined within surface-modified microchannels.



channels with B7

Figure. Polarizing optical microscope image of the B7 liquid crystal phase of a banana-shaped molecule confined in silicon-based channels with 5 m depth and width. The colorful ribbon- or filament-like structures grow very slowly through the channels while being cooled at a rate of -0.02C/min from the isotropic phase. This confined liquid crystal texture shows several interesting periodic morphologies under crossed-polarizers. The image is approximately 350 x 240 m and was obtained with a 40X objective.

Text and image contributed by Dong Ki Yoon.