Bundles of fluid fibers formed by bent-core molecules

The internal structures, stability, and elastic properties of free-standing filament bundles of bent-core smectic liquid crystals are studied using polarizing microscopy, scanning electron microscopy, and a customized cantilever containing, temperature controlled heat stage for force measurements. We find that in bundles, the individual filaments fuse together to form semiseparable filaments with radii approximately two and three times larger than the individual fibers. We also find that the effective surface tension of wide bundles is about 10% smaller than a single filament. Finally, we describe the metastable coexistences of single fibers within the bundles that lead to bending of the bundles. All of these observations were explained with simple macroscopic models.