Self‐Assembly of Bent‐Core Nematics in Nanopores

Bent-core nematic liquid crystals exhibit unique properties, including giantflexoelectricity and polar electro-optic responses, making them ideal forenergy conversion and electro-optic applications. When confined innanopores, they can stabilize chiral nanostructures, enhance polar order, andenable defect-driven switching – offering potential in nanofluidics, sensing,and adaptive optics. The thermotropic ordering of the bent-core dimer CB7CBconfined in anodic aluminum oxide (AAO) and silica membranes withprecisely engineered cylindrical nanochannels – ranging from just a fewnanometers to several hundred nanometers–is examined. These well-alignednanochannels enable high-resolution polarimetry studies of opticalanisotropy, revealing how geometric confinement affects molecularorganization and phase behavior. Under weak confinement, CB7CB forms alayered heterophase structure, with nematic, splay-bent, and twist-bentheliconical phases likely arranged concentrically. As confinement increases, aLandau-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 underconfinement closely resemble those seen under applied electric fields,revealing a parallel between geometric and electro-optic effects. Overall, thiswork demonstrates how nanoconfinement allows one to systematically tailorthe self-assembly and optical behavior of bent-core nematics, enabling novelfunctionalities in responsive and anisotropic materials.