Nanostructures Of Bent-Shaped And Polar Liquid Crystals
Author: Rony Saha
Publisher:
Published: 2022
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKThe phases of matter between isotropic liquid and well-ordered crystalline solid phases are known as liquid crystal phases. The molecular architecture, which includes structure, polarity, and topology, influences the liquid crystal phases formed by mesomorphic materials. The most common and widely studied liquid crystal phase is the nematic phase formed by rod-like molecules. The molecules in this phase have only orientational order, which means they prefer to align along a single axis while their positions are random addition they do not have polarity. Flexible bent-shape molecules where an odd number of methylene groups connect two rigid arms exhibit twist-bend nematic (N_TB)" phase. In the N_TB phase, the molecules have a heliconical structure with a 10 nm range pich. Rigid achiral bent-shape materials typically show polar and chiral smectic structures because tilted and polar packing makes each smectic layer chiral. Lastly, rod-shaped molecules with large (about 10 Debye) dipole moments form the ferroelectric nematic phase predicted by Max Born in 1916 but experimentally observed only a few years ago. In my dissertation, I will describe various studies of the nanostructure of different flexibly bent-core liquid crystal materials exhibiting the N_TB Phase, structures of ferroelectric and antiferroelectric smectic phases of rigid bent-shape materials, and multiple ferroelectric nematic phases of a highly polar rod-shape substance.
