Bent-Core Liquid Crystal Elastomers
Journal of Materials Chemistry
Liquid crystal (LC) elastomers with bent-core side-groups incorporate the properties of bent-core liquid crystals in a flexible and self-supporting polymer network. Bent-core liquid crystal elastomers (BCEs) with uniform alignment were prepared by attaching a reactive bent-core LC to poly(hydrogenmethylsiloxane) and crosslinking with a divinyl crosslinker. Phase behavior studies indicate a nematic phase over a wide temperature range that approaches room temperature, and thermoelastic measurements show that these BCEs can reversibly change their length by more than a factor of two upon heating and cooling. Small-angle X-ray scattering studies reveal multiple, broad low-angle peaks consistent with short-range smectic C order of the bent-core side groups. A comparison of these patterns with predictions of a Landau model for short-range smectic C order shows that the length scale for smectic ordering in BCEs is similar to that seen in pure bent-core LCs. The combination of rubber elasticity and smectic ordering of the bent-core side groups suggests that BCEs may be promising materials for sensing, actuating, and other advanced applications.
Verduzco, Rafael; Luchette, Paul; Hong, Seung Ho; Harden, John; DiMasi, Elaine; Palffy-Muhoray, Peter; Kilbey, S. Michael II; Gleeson, Jim T.; and Jákli, Antal (2010). Bent-Core Liquid Crystal Elastomers. Journal of Materials Chemistry 20(39), 8488-8495. Retrieved from http://digitalcommons.kent.edu/cpippubs/7