The Origin of High Optical Tilt in a Homologous Series of Fluorinated Antiferroelectric Liquid Crystals

Abstract

The compounds from the fluorinated nF6B (n ¼ 1,2,3,4,5,6,7) homologous series were investigated by means of optical, electrooptical, refractometrical, dielectric, densytometric, X-ray and IR spectroscopy methods. For some compounds being a subject of investigations a computer simulation of molecular properties were done. In our opinion high value of optical tilt h o angle in comparison with a tilt angle obtained from X-ray measurements can be interpreted in terms of de Vries model of SmA Ã phases as well as of dimers creation process.

An Influence of a Single Fluorine Atom Position in the Molecular Rigid Core on Physical Properties of Orthoconic Antiferroelectric Liquid Crystal

“…Together with the strong electroclinic effect the above suggest that all materials can be regarded as those having Sm A * of deVries type [8,[22][23][24].…”

“…The tilt angle θ and the spontaneous polarizations P s , were investigated by standard methods [8] using specially prepared in our laboratory 1.6 [µm] thick cells filled with material under study in isotropic phase by capillary action. Cell surfaces with ITO conducting layers were spincoated by RN1199 (Nissan Chemicals) polyimide followed by suitable, antiparallel rubbing.…”

“…Conventional AFLC materials (also called regular) are tilted between 20 • and 35 • . AFLC materials exhibiting the extremely high tilt angle are of the biggest interest nowadays [7,8]. So called Orthoconic Antiferroelectric Smectic Liquid Crystals (OAFLC's) allow the more perspective and simple method of eliminating the problem of contrast of AFLC displays [9,10].…”

Electrooptic study of antiferroelectric mixtures for display application

“…AFLC having tilt angle equal to 45 degree, the so-called orthoconic antiferroelectric liquid crystal (OAFLC), could give a perfect dark state between crossed polarizers [5][6][7]. From this point of view, the liquid crystalline mixtures fulfil such requirements.…”

Effect of fluorination of molecular rigid core in liquid crystal biphenyl benzoate based homologous series

“…A number of structural and physical parameters were studied by standard methods [5][6][7]. The tilt angles q, the spontaneous polarizations P s , the switching times t and the rotational viscosity g were investigated using 1.6−µm thick cells with ITO electrodes, specially prepared in our labora− tory.…”