Bowlics: history, advances and applications

Abstract

There are three types of liquid crystals (LCs) in the world: rodics, discotics and bowlics, corresponding to one-, two-and three-dimensional molecules, respectively. The rodics were discovered by the Austrian, F. Reinitzer, in 1888 and is the material behind the LC display industry of $100 billion annually. The discotics were discovered by S. Chandrasekhar's team in India, in 1977. The third type, bowlics, was proposed by a Chinese, LIN Lei (Lui LAM), in 1982 while working at the Institute of Physics, CAS, Beijing. Distinguished from the rodic and the discotic, a bowlic molecule breaks the updown symmetry, and bowlic LCs are one of excellent candidates for switchable ferroelectrics with great potential applications in ultrahigh-density memory devices. The importance of strategic bowlic materials has recently attracted increasing attention of scientists from multiple disciplines and engineers from different backgrounds. In this review, the history of bowlics and their recent advances in molecular design, synthesis and applications are discussed.

Nature‐Inspired Emerging Chiral Liquid Crystal Nanostructures: From Molecular Self‐Assembly to DNA Mesophase and Nanocolloids

“…[1,[5][6][7][8][9][10][11][12][13][14] The molecular geometry of LCs can be rod-like (calamitic), disklike (discotic), bowl-like (bowlic), bent-shape, etc. [1,[60][61][62][63][64][65][66] Generally, there are two most popular methods to introduce chirality into thermotropic LCs. The first one is to develop single-component chiral mesogen (LC-forming compound).…”

“…In thermotropic LCs, the mesophases are formed upon changing the temperature of mesomorphic materials, and thus liquid crystalline phases can only occur in a certain temperature range . The molecular geometry of LCs can be rod‐like (calamitic), disk‐like (discotic), bowl‐like (bowlic), bent‐shape, etc . Generally, there are two most popular methods to introduce chirality into thermotropic LCs.…”

Phase Behavior of Bowl‐Shaped Colloids: Order and Dynamics in Plastic Crystals and Glasses

“…These anisotropic colloids can be obtained via polymerization‐induced buckling instability, the collapse of thin hollow spherical shells, or temperature controlled swelling with hydrocarbons . Well‐known in the molecular liquid crystal community, bowlic molecules are of interest due to the up‐down symmetry breaking . This geometry of the molecules offers the possibility to form stacks and columns that are promising for the formation of defect‐free columnar phases or specialized antiferroelectric phases .…”

“…Well‐known in the molecular liquid crystal community, bowlic molecules are of interest due to the up‐down symmetry breaking . This geometry of the molecules offers the possibility to form stacks and columns that are promising for the formation of defect‐free columnar phases or specialized antiferroelectric phases . Due to their larger size, bowl‐shaped nanoparticles and colloids are of interest as superhydrophobic and infrared blocking coatings, contrast agents for optical coherence tomography imaging, or superstructures with a full photonic bandgap .…”

Potential of Liquid-Crystal Materials for Millimeter-Wave Application

“…An LC device exhibits compactness, lightweight, low power consumption, and low driving voltage for all application fields in the optics and photonics [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Furthermore, some optical control devices, such as variable focusing lenses, beam-steering prisms, and polarization control devices, gained attention in conjunction with conventional LC device applications, such as spatial light modulators and phase shifters [12][13][14][15][16][17][18]. Recently, it became evident that LC materials have a large birefringence in the wider frequency range of the electromagnetic wave spectra, such as microwave, millimeter wave (MMW), and THz regions [19][20][21][22].…”