摘要:

We obtained polymer dispersed nematic liquid crystal films E7/PMMA. In order to induce anisotropy and consequently electrical polarization, the films have been hot stretched and pressed.

ISSN:1058-725X    

DOI:10.1080/10587250008023276

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Four new chiral homologous series of ferroelectric liquid crystals S-(-)-4-(2-n-alkoxy-propionyloxy)biphenyl-4′-n-alkoxy-3,5-dimethylbenzoate (DMn/mseries) having O-substituted S-(-)-lactic acid as terminal group were synthesized, and characterized. They showed monotropic chiral smectic C and chiral nematic mesophases, and two representatives exhibited blue phase as well. Binary mixtures of these compounds were investigated. The effect of the lateral methyl substitutents and the length of the terminal groups on the chiral and non-chiral parts were investigated.

ISSN:1058-725X    

DOI:10.1080/10587250008023277

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A new method of the formulation of liquid crystalline antiferroelectric (CA*) materials from smectic C* and smectic A components is demonstrated. The phase diagrams of the induced CA* systems and the temperature dependence of their smectic layer spacings and switching behavior are shown.

ISSN:1058-725X    

DOI:10.1080/10587250008023278

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Chiral (S) 4-(1-methylheptyloxycarbonyl)phenyl 4′-(ω-trifluoroethoxyalcoxy)biphenyl-4-carboxylates and 4′-(ω-trifluoro-butanoyloxyalcoxybiphenyl)carboxylates were prepared and their phase transitions and the temperature dependence of the smectic layer spacings, tilt angle, spontaneous polarization, threshold and switching times for the antiferroelecrtic—ferroelectric transition were measured.

ISSN:1058-725X    

DOI:10.1080/10587250008023279

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

We report measurements on the bistability of the electrooptic response of a commercially available material (CS2005) and an experimental liquid crystal material (CDRR8) based on an organosiloxane structure. Both materials have a first order transition to the SmC* phase. CS2005 gave the normal monostable behaviour with layers tilted with respect to the rubbing direction. However, the second material, CDRR8, exhibited true bistability and at the same time its smectic layers were found to lie perpendicularly to the rubbing direction. We were able to control the bistable behaviour of the CDRR8 material by means of layer rotation using asymmetrical triangular pulses. As expected the sample shows a monostable response each time the layers are rotated so that one of the two switched states approaches the rubbing direction.

ISSN:1058-725X    

DOI:10.1080/10587250008023280

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Ferroelectric liquid crystal devices are primarily of interest owing to their truly bi-stable operation and fast switching times. At present our understanding of the switching processes in ferroelectric liquid crystal cells is incomplete. In order to develop a more complete understanding it is necessary to have a detailed knowledge of the optical tensor configuration adopted by liquid crystalline materials in cells. In this paper we present results of a half-leaky guided mode study of voltage induced elastic deformations of the director profile in a cell containing a homogeneously aligned 40% chiral mixture of the ferroelectric liquid crystal SCE8. The experimentally deduced changes in the director structure are highly accurate and may be used to test theoretical models of surface stabilised ferroelectric liquid crystal devices.

ISSN:1058-725X    

DOI:10.1080/10587250008023281

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

We have investigated theoretically chevron formation in smectic C materials and the transformation of this chevron structure to a tilted layer structure as the cell is sheared. We find a series of transition temperatures at which the behaviour of the cell critically changes and the number of possible cell configurations increases. These structures include tilted layers, single chevrons, multiple chevrons and asymmetric chevrons. Although most of the more complex multiple chevron structures are unstable we show, using a relatively simple dynamical model, that these structures may appear transiently during the formation of the stable, single chevron structure.

ISSN:1058-725X    

DOI:10.1080/10587250008023282

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Three relaxation modes are identified in the surface stabilized ferroelectric liquid crystal from the Tikhonov regularization analysis of the low frequency dielectric data. The field strength dependence of the relaxation frequency and mode strength for each relaxation mode was studied in detail so that we could help better clarifying for the characteristic relaxation mechanisms of the three low frequency modes recently found by various authors.

ISSN:1058-725X    

DOI:10.1080/10587250008023283

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

PDLC structures containing ferroelectric and antiferroelectric liquid crystal phase of the same material have been obtained. The initial studies of electrooptical properties of those materials have been done.

ISSN:1058-725X    

DOI:10.1080/10587250008023284

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Series of pyrimidine and pyridine analogous compounds have been developed in order to interpret the relationship between stability of antiferroelectricity and the conjugation along the long axis of the molecule. On the appearance of antiferroelectricity, the longitudinal polarization of whole molecules promotes to stabilize the antiferroelectricity.

ISSN:1058-725X    

DOI:10.1080/10587250008023285

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor