A novel technique for characterizing the sense of twisting in cholesteric liquid crystals

Hashimoto, Takeji; Ebisu, Satoshi; Kawai, Hiromichi

doi:10.1002/pol.1980.130180810

Cited by 18 publications

(6 citation statements)

References 7 publications

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“…The DCE.solution thus has negative rotatory power and left-handed cholesteric twisting. 6 The sense of distortion in the depolarized "cholesteric scattering pattern" depends not only Polymer J., Vol. 13, No.7, 1981 on the solvent but also on temperature as dem-.…”

Section: Resultsmentioning

confidence: 99%

Supramolecular Structure of Polypeptides in Concentrated Solutions and Films. II. Small-Angle Light Scattering from Cholesteric Mesophase

Hashimoto

Ebisu

Inaba

et al. 1981

Polym J

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ABSTRACT:The cholesteric mesophase of poly(y-benzyl L-gultamate) in concentrated solutions of helicogenic solvents was investigated by the laser-light scattering technique. The observed, elastic scattering intensity distributions are theoretically explained in terms of the cholesteric domains embedded in an optically active medium. Analysis of the scattering patterns provides information on the identity period and sense of the cholesteric twisting.KEY WORDSThe laser-light scattering technique has been developed to characterize the supramolecular structure of polymeric systems in solution and in the liquid and solid states. In this series of papers, we study the application of this technique to the supramolecular structure of polypeptides in concentrated solutions and in solids.A number of reports have been published on the supramolecular structure of polymer liquid crystals. There are even a few papers dealing with the application of the scattering technique for analyzing the cholesteric pitch 1 • 2 or to qualitatively the orientation correlations (which exist in solutions and in solids) and variation in these with solvent, film preparing conditions3.4 and applied fields. 5 Our main purpose in this paper is to gain some insight into the elastic light scattering behavior of cholesteric liquid crystals so as to further expand applicability of this technique.We shall study, both theoretically and experimen-* Present address:

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Section: Resultsmentioning

confidence: 99%

Supramolecular Structure of Polypeptides in Concentrated Solutions and Films. II. Small-Angle Light Scattering from Cholesteric Mesophase

Hashimoto

Ebisu

Inaba

et al. 1981

Polym J

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“…For example the scattering maximum in the large-angle region occurs at the scattering angle reciprocally related to the identity period S of the alternating bright and white stripes in the micrograph shown in Figure 9(a), i.e., half the distance of the cholesteric pitch.1S. 16 Figure l 0 shows the micrographs under crossed polarizers corresponding to the scattering patterns shown in Figure 4 for the solutions enclosed in a cell. The polarization directions are set vertically and horizontally.…”

Section: Supramolecular Structure In Concentrated Solutionsmentioning

confidence: 99%

“…The effect of the optical rotation on the "ring" scattering, i.e., the scattering maximum arising from the cholesteric twisting will be described in detail in a subsequent paper. 15 Polymer J., Vol. 12, No.…”

Section: O• Kd=0°mentioning

confidence: 99%

Supramolecular Structure of Polypeptides in Concentrated Solutions and Films. I. Origin of Rod-like Scattering and Effect of Form-Optical Rotation

Hashimoto

Ijitsu

Yamaguchi

et al. 1980

Polym J

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Supramolecular structures of poly(y-benzyl L-gultamate) in concentrated solutions of helicogenic solvents and in solid state were investigated by laser-light scattering technique. The depolarized elastic scattering indicates that there exists two types of rod-like scattering with X-type (having maximum intensity at odd multiples of the azimuthal angle, and +-type (having maximum intensity at multiples of I'= 90°) angular distributions. The structural origin of such rod-like scattering and the effect of form-optical rotation on the rod-like scattering are discussed. KEY WORDS Supramolecular Structure I Poly(y-benzyl L-gultamate) I Liquid Crystals I Depolarized Light Scattering I Form Optical Rotation I Rod-like Scattering I

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“…This sample had spherical morphology44 (at +s = 0.265) which, being favored over planar morphology, should have a higher T, than calculated here. Finally, an adjustment of SS -SE to 0.88from 0.80, inferred5 from using the Step profile-would lead the present model to match the Roe result when the q = 5 profile is used.Discussion of the tapered SI copolymer of Hashimoto et al39 is not easy in the context of the present theory for distinct-block molecules. Qualitatively, however, that result is understandable in the sense that tapering makes the two ends of the molecule more compatible than would be so for SI blocks described by the theory.…”

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Influence of the interphase on block copolymer thermodynamics: Extension of the leary model

Henderson

Williams

1985

J. Polym. Sci. Polym. Phys. Ed.

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synopsisThe Leary-Williams model for the microphase thermodynamics of triblock ABA copolymers has been modified to accommodate deviations from homogeneous randomcoil configurations in the Bchain dimensions as well as in those of the A chains, and has also been extended to cover the case of diblock AB copolymers. Only planar morphology is considered, but qualitative conclusions reported herein are expected to hold for other morphologies as well. The focus is on interphase thickness AT, with predictions made also for separation temperature T, and planar repeat distance D. Results are presented as-systematic functions of copolymer composition (0 I + A I l), total molar volume (25,000 I V I 4 x 106 cmS/g moll, block architecture (AB vs. ABA), temperature (298,373 K), and for five different interphase composition profiles.In most cases, A represents a polystyrene block and B a butadiene block in these calculation_s.Predictions for AT increase with temperature and depend on architecture, profile, and V; comparisons with data are close. in the range 1-0 A. It is shown that T, depends strongly on profile choice and (PA, reaching a maximum in the +,midrange but always with +. A > 0.5. The major prameter influencing D (at c o n + n t V ) -k architectcre, with D(SB) = ZMSBS), and D(V) varies from D a V076 at low Vto D a V o S a t high V.

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A novel technique for characterizing the sense of twisting in cholesteric liquid crystals

Cited by 18 publications

References 7 publications

Supramolecular Structure of Polypeptides in Concentrated Solutions and Films. II. Small-Angle Light Scattering from Cholesteric Mesophase

Supramolecular Structure of Polypeptides in Concentrated Solutions and Films. II. Small-Angle Light Scattering from Cholesteric Mesophase

Supramolecular Structure of Polypeptides in Concentrated Solutions and Films. I. Origin of Rod-like Scattering and Effect of Form-Optical Rotation

Influence of the interphase on block copolymer thermodynamics: Extension of the leary model

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