We review recent developments in the use of the phase separated composite organic film method and the fabrication of liquid crystal (LC) electro-optical devices using a single glass substrate using this method. The LC layer is confined between a film of solidified polymer layer on one side and the glass substrate on the other. The solidified polymer layer adjacent to and parallel to the LC layer is created by UV induced phase separation of a mixture of LC and prepolymer. Electro-optical properties of these devices demonstrate their high technological potential in light weight and hand-held electronic products.

A method of preparing liquid crystal devices by phase separation of liquid crystal from its solution in a prepolymer, which results in adjacent layers of liquid crystal and polymer, is described. Liquid crystals in these phase-separated composite films exhibit electro-optical properties not observed in devices prepared by conventional methods, polymer dispersion, or polymer-stabilization methods. Devices incorporating ferroelectric liquid crystals have gray scale and switch 100 times faster at low fields than conventional surface-stabilized devices. This method makes it possible to prepare devices with liquid crystal film thickness comparable to optical wavelengths.

AbstractVery flexible nematic LCDS have been built with plastic substrates using phase separated composite organic method. A study of electro‐optical properties of these displays shows a low voltage operation, high contrast, and a high degree of mechanical flexibility.

AbstractA new structure of a light modulating element based on ferroelectric liquid crystal (FLC) is fabricated. It is prepared by the photopolymerization induced phase separation of an initially isotropic solution of FLC and a prepolymer. The element consists of two successive layers parallel to the cell substrates. One layer is the isotropic polymer and the other is the FLC macroscopically aligned by a rubbed alignment layer. A study of electrooptical properties of these FLC elements reveals a continuous gray scale, contrast ratio 100:1 along the cell normal, line addressing times of microseconds in the active mode. Because of their internal structure, they are insensitive to mechanical stress.

An electro-optical element based on antiferroelectric liquid crystal (AFLC) has been prepared by photopolymerization-induced anisotropic phase separation of a solution of an AFLC and a prepolymer. It consists of two adjacent layers, one comprised of the isotropic polymer and the other of the AFLC aligned by surface treatment of the adjacent substrate. The electro-optical properties show that these devices are either optically monostable or multistable (at zero field) with maximum memory angle of ∼15°. A qualitative model to describe the origin of memory in these AFLC/polymer composites is discussed.

Electrooptical properties of PDFLC samples, aligned by shearing, are investigated. Experimental results on apparent switching angle, dynamical switching behaviour at different electric fields, and multistable response of PIPS PDFLC are presented. A qualitative model of the PDFLC behaviour is suggested to explain the results. The model considers FLC in the droplets as FLC gel, the polymer network throughout the droplet as continuous or broken, and domain wall switching at the chevron interface inside the droplet allowed by the broken or prohibited by the continuous network. The multistability is explained as being due to completed switching in microdomains of the PDFLC droplet or caused by stabilization instantaneous domain wall positions by the network.

Abstract Interaction of surface charges of the FLC spontaneous polarization and mobile ions of a surfac-tant in an alignment layer results in a monostable response of the FLC. Internal field in the FLC bulk induced by the ions of the surfactant in the alignment layer leads to the monostability. Changing the external voltage parameters it is possible to obtain a modulation of a transmitted light (analogue grey scale) in the FLC cells with the alignment layers contained surfactant.

The review of methods to measure Ferroelectric Liquid Crystal (FLC) anchoring strength are given. The methods are based on measuring the hysteresis and electrooptical dynamic response of FLC. The results of measurements are presented. The ways of future investigations in the field are discussed.

A new series of optically active compounds have been prepared using 4.4 ''-terphenyldicarboxylic acid and S-2-alcoxypropanols-1. These ace Sm*C, SmA and N* chemically stable - especially with regard to racemization and UV-light compounds with a snail P-S value, high twisting power and left handedness of helix.

Long-term perfect bistable snitching of 1,5 mu m thick Ferroelectric Liquid Crystal (FLC) cell oriented by photoanisotropic (PA) films was demonstrated even in case of a large spontaneous polarization 2 orientation Ps=100nC/cm(2). The condition of a good SmC* quality was shown to be the existence of a nematic phase N*. The bistability properties of PA-films aligned FLC cell, kept for a while in a short-curcuiting state, are easily restored, which is not observed in FLC cells oriented by usual rubbing technique.