2024/07/15 by Jean de Dieu Niyonzima, Haïfa Jeridi, Niyonzima, Jean de Dieu +31
Materials Science · Medicine · Computer Science · #Liquid Crystal Research Advancements #Ocular Surface and Contact Lens #Nonlinear Dynamics and Pattern Formation
paper · pdf · doi:10.48550/arxiv.2407.10598
Smectic liquid crystals can be viewed as model systems for lamellar structures for which there has been extensive theoretical development. We demonstrate that a nonlinear energy description is required with respect to the usual Landau-de Gennes elasticity in order to explain the observed layer spacing of highly curved smectic layers. Using X-ray diffraction we have quantitatively determined the dilation of bent layers distorted by antagonistic anchoring (as high as 1.8% of dilation for the most bent smectic layers) and accurately described it by the minimal nonlinear expression for energy. We observe a 1° tilt of planar layers that are connected to the curved layers. This value is consistent with simple energetic calculations, demonstrating how the bending energy impacts the overall structure of a thin distorted smectic film. Finally, we show that combined X-ray measurements and theoretical modeling allow for the quantitative determination of the number of curved smectic layers and of the resulting thickness of the dilated region with unprecedented precision.