Elastic and flexoelectric properties of chiral smectic-C phase and symmetry considerations on ferroelectric liquid-crystal cells

Dahl, Ingolf; Lagerwall, S. T.

doi:10.1080/00150198408237871

Cited by 120 publications

(32 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the treatment of the Orsay group is less general as it holds only for small displacements. Agreement is found with the result of Dahl and Lagerwall [8] and Dahl [9] as well as with the result of Carlsson, Stewart, and Leslie [10] for Sm-C'. Agreement is also found with de Gennes in case of small displacements [11].However, opinions regarding the nature of the equilibrium state di8'er.…”

Section: Introductionsupporting

confidence: 87%

“…Carlsson, Stewart, and Leslie only raise the question whether this assumption is justified, whereas de Gennes agrees with the assumption adhered to in the present paper. The elastic constants for Sm-C' given in Table I are related to the elastic constants of the Orsay group [7] and Dahl and Lagerwall [8] according to Results are presented for the antiferroelectric Sm-C& [12], and for the ferrielectric Sm-C* and Sm-C' [13] phases. It should be noted that the macroscopic symmetry of the ferrielectric chiral smectics is the same as that of the ferroelectric Sm-C*, although their microscopic structures differ.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Elasticity theory of smectic and canonic mesophases

Stallinga

Vertogen

1995

Phys. Rev. E

View full text Add to dashboard Cite

The general theory of elasticity for smectic and canonic mesophases is formulated, starting from the assumption that the equilibrium state is spatially periodic. The various surface terms appearing in the deformation free energy density are considered as well. The efFective description of the elastic behavior of a general nonchiral smectic mesophase involves one positional elastic constant, 16 bulk orientational elastic constants, and six surface orientational elastic constants. One additional bulk orientational elastic constant is required for the description of a general chiral smectic mesophase. The efFective description of the elastic behavior of a general nonchiral canonic mesophase involves six positional elastic constants and three bulk orientational elastic constants. In this case the property of chirality does not introduce additional orientational elastic constants. The elastic constants for some relevant smectic and canonic mesophases are given, including the elastic constants for the antiferroelectric Sm-C& and ferrielectric Sm-C' and Sm-C~phases. PACS number(s): 03.40.Dz

show abstract

Section: Introductionsupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Elasticity theory of smectic and canonic mesophases

Stallinga

Vertogen

1995

Phys. Rev. E

View full text Add to dashboard Cite

show abstract

“…ap [15] These yield the analytical expressions for the pitch angle / and radius pn(w) of an n-bilayer helical ribbon: Thus, we have obtained the interesting result that regardless of the edges, the optimal pitch angle is equal to the molecular phase angle of the cylindrically grown tubule having a minimum elastic free energy Gin.ule The pitch angle is also entirely independent of other properties ofthe ribbon such as the width w and elastic moduli K?P, K*, An, and Tn. For an isotropic bilayer (K C = KPP), the pitch angle is 450, identical to Helfrich and Prost's results (11).…”

mentioning

confidence: 99%

Elastic free energy of anisotropic helical ribbons as metastable intermediates in the crystallization of cholesterol.

Chung

Benedek

Konikoff

et al. 1993

Proc. Natl. Acad. Sci. U.S.A.

164

170

View full text Add to dashboard Cite

We report measurements of the geometrical a In 1986, Helfrich (10) proposed a simple elastic model in which the optimal shape of a helical ribbon is controlled by a balance between bending of the ribbon and torsion of its edges, leading to a universal pitch angle of 450 for an elastically isotropic ribbon. Two years later Helfrich and Prost (11) generalized the bending free energy for anisotropic bilayers. To account for the lack of mirror reflection symmetry of bilayers of chiral molecules, they also added a term linear in the surface curvature to the elastic free energy (11).Despite these refinements, the analysis of the pitch angle was made only for an isotropic bilayer and the pitch angle remained 45°. In 1990, Ou-Yang and Liu (12) modeled the The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact. helical ribbon as a cholesteric liquid crystal layer and also obtained the pitch angle of 45°.Herein, we describe experimentally observed helical ribbon structures with either of two distinctive pitch angles: 540 or 110. We also present a form for the elastic free energy of anisotropic chiral bilayers that provides analytical expressions for the geometrical features and growth of the helical ribbon structures observed in our biles. MATERIALS AND METHODSAll model biles were composed of the common bile salt sodium taurocholate, lecithin, and cholesterol in a molar ratio of 97.5:0.8:1.7. Sodium taurocholate (Sigma) was recrystallized and found to be >98% pure by HPLC and TLC. Cholesterol (Nu Chek Prep, Elysian, MN) was >99% pure by TLC, GC, and HPLC. Grade I egg yolk lecithin (Lipid Products, Nutley, U.K.) was >99% pure by TLC. Synthetic sn-1-16:0-sn-2-18:1 lecithin (lecithin I) and sn-1-16:0-sn-2-16:0 lecithin (lecithin II) were obtained from Avanti Polar Lipids. Model biles A, B, C, and D contained lecithin I, a 1:1 mixture of lecithin I and lecithin II, egg yolk lecithin, and lecithin II, respectively. Native bile was a generous gift from M. Cahalane (Beth Israel Hospital, Boston) (2). Using TLC, no degradation of the components of bile was observed during our experiments.At a total lipid concentration of 70 mg/ml (0.15 M NaCl/3 mM NaN3), all four model biles formed micellar solutions with a mean hydrodynamic radius of 17 ± 5 A (2, 13).Meticulous precautions were taken to reduce the nucleating effect of dust. A 5-ml vial with a Teflon septum cap was acid-cleaned, rinsed, filled with Milli-Q water (Millipore), Abbreviation: ChM, cholesterol monohydrate crystal.§Present address:

show abstract

“…Tilted smectic liquid crystals have low symmetry and for this reason many elastic coefficients [4] are needed to describe their properties. In this paper we limited ourselves to determination of the twist elastic constant B 3 (according to the notation of Ref.…”

Section: Principle Of Measurementmentioning

confidence: 99%

“…The sensitivity of the liquid crysta1 cell on various external factors and the value of the switching threshold depends on elastic coefficients, first of all on the twist elastic constant for the c director B 3 (according to the notation of de Gennes [3], used also by Dahl and Lagerwall [4]). Therefore determination of this parameter is of large technical value.…”

Section: Introductionmentioning

confidence: 99%

Determination of bulk values of twist elasticity coefficient in a chiral smectic C* liquid crystal

Kuczyński

Nowicka

Dardas

et al. 2010

Opto-Electronics Review

View full text Add to dashboard Cite

A method is described for determination of bulk values of a twist elastic coefficient for smectic c-director in chiral smectic liquid crystals with a helical structure. The method was applied to 4-methylbutyloxy phenyl-4-octyloxy-benzoate (C8) in the chiral smectic C* phase. The measurements were performed using optical detection in a small deformation limit. In contrast to the usual methods, initial deformation of the helix (caused by strong surface interactions) was avoided by using homeotropic aligned thick samples. The critical temperature dependence of the measured coefficient was observed. The relation between the measured parameter and the smectic C order parameter is presented.

show abstract

Elastic and flexoelectric properties of chiral smectic-C phase and symmetry considerations on ferroelectric liquid-crystal cells

Cited by 120 publications

References 12 publications

Elasticity theory of smectic and canonic mesophases

Elasticity theory of smectic and canonic mesophases

Elastic free energy of anisotropic helical ribbons as metastable intermediates in the crystallization of cholesterol.

Determination of bulk values of twist elasticity coefficient in a chiral smectic C* liquid crystal

Contact Info

Product

Resources

About