Self‐Assembly of Bent‐Core Nematics in Nanopores

Abstract Bent‐core nematic liquid crystals exhibit unique properties, including giant flexoelectricity and polar electro‐optic responses, making them ideal for energy conversion and electro‐optic applications. When confined in nanopores, they can stabilize chiral nanostructures, enhance polar order, and enable defect‐driven switching – offering potential in nanofluidics, sensing, and adaptive optics. The thermotropic ordering of the bent‐core dimer CB7CB confined in anodic aluminum oxide (AAO) and silica membranes with precisely engineered cylindrical nanochannels – ranging from just a few nanometers to several hundred nanometers–is examined. These well‐aligned nanochannels enable high‐resolution polarimetry studies of optical anisotropy, revealing how geometric confinement affects molecular organization and phase behavior. Under weak confinement, CB7CB forms a layered heterophase structure, with nematic, splay‐bent, and twist‐bent heliconical phases likely arranged concentrically. As confinement increases, a Landau‐de Gennes analysis shows that ordered phases are suppressed, leaving only a paranematic phase under strong spatial constraints. Remarkably, temperature‐dependent changes in optical birefringence under confinement closely resemble those seen under applied electric fields, revealing a parallel between geometric and electro‐optic effects. Overall, this work demonstrates how nanoconfinement allows one to systematically tailor the self‐assembly and optical behavior of bent‐core nematics, enabling novel functionalities in responsive and anisotropic materials.