Structure and Correlations in Smectic B, F and I Phases

Gane, Patrick; Leadbetter, A. J.; Wrighton, P. G.

doi:10.1080/00268948108072678

Cited by 120 publications

(36 citation statements)

References 22 publications

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“…They are described as a one-dimensional crystalline stacking of positionally uncorrelated layers with long range three-dimensional orientational order [5][6][7]. For SF, the in-plane positional order is only short range, whereas for S, it is quasi long range.…”

Section: Introductionmentioning

confidence: 99%

“…For SF, the in-plane positional order is only short range, whereas for S, it is quasi long range. Molecules are tilted towards the long and the short side of the local rectangular cell for SF and S, [7] respectively. A similar mesophase, in which however the molecules are perpendicular with respect to the plane of the layers, has also been identified; this is a hexatic modification of SB [8].…”

Section: Introductionmentioning

confidence: 99%

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Volume and X-ray diffraction study of terephthal-bis-4,n-decylaniline (TBDA)

1986

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Résumé. 2014 On présente une étude systématique du polymorphisme smectique du TBDA par dilatométrie et diffraction des rayons X aux petits angles. En conjuguant les données expérimentales recueillies à l'aide des deux techniques, on a déterminé l'évolution de l'aire moléculaire et l'angle d'inclinaison des molécules en fonction de la température. On a, enfin, discuté les résultats obtenus notamment en relation avec la nature et l'extension de l'ordre dans les mésophases smectiques F, I et C.Abstract 2014 This is a systematic study of the smectic polymorphism of TBDA, carried out using dilatometry and small-angle X-ray diffraction. By combining the experimental data collected by the two techniques, the thermal evolution of the molecular area and the tilt angle of the molecules have been determined The results are discussed particularly in relation to the nature and the spatial extension of order in the smectic F, I and C mesophases.J. Physique 47 (1986)

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Volume and X-ray diffraction study of terephthal-bis-4,n-decylaniline (TBDA)

1986

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“…Therefore, the direction of the tilt is decoupled from the direction of the nonhexagonal distortion of the lattice. This is unlike bulk crystalline phases (12) or smectic-I or -J liquid crystalline phases (33), where the tilt direction is strongly correlated to the lattice directions. This decoupling of the tilt and lattice distortion in the low-temperature phase may well be a kinetic effect.…”

Section: Tilt Orderingmentioning

confidence: 84%

Molecular structure of surfactant-coated surfaces

Garoff

1987

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

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The structure of surfactants on solid surfaces arises from the competition between the molecular forces that drive the formation of bulk phases of these molecules and the constraints of the solid interface. These monolayers exhibit bond-oriented ordering and undergo both reversible and irreversible phase transformations.Historically, the impetus for studying monomolecular layers at interfaces was the dramatic alteration of the interfacial tension of a fluid by such layers (1). This area of research has greatly expanded over the years, and many other macroscopic properties of an interface have been found to be altered by these monolayers. Examples of these interfacial properties include the wetting of a solid by a liquid, the lubrication of two solid surfaces moving past each other, the transport of materials between the bulk phases separated by the monolayer, and the alignment of bulk liquid crystalline phases in contact with the monolayer. In more recent times, similar monolayers have been recognized as potential models for components of cell membranes and as constituents for multilayer assemblies, molecularly engineered to produce electronic and optical devices. These macroscopic interfacial properties which are so greatly affected by these monolayers have tremendous impact on a wide variety of technologies. The search for the origins of these macroscopic interfacial phenomena has led us to a close examination of the structure of the monomolecular films that so dramatically alter them. However, as we have explored these origins, we have found that the intra-and intermolecular order in surfactant monolayers on solid surfaces is a topic of rich scientific interest on its own.The state of ordering in these monolayers on solid surfaces is different than that in bulk lamellar phases (e.g., smectic thermotropic liquid crystals, lamellar lyotropic liquid crystals, and lamellar crystals) of these molecules. This structure arises from a competition between the intermolecular forces responsible for the order in bulk phases and the unique influences and constraints of the interfacial region in which the monolayer lies. Frequently, ordering in monolayers, particularly on the nonideal, hydrophilic substrates usually encountered, is assumed to be some kinetically frozen configuration, far from equilibrium, and on the verge of collapse. Evidence of lattice expansions, reversible phase transitions, and long-term stability indicates that these monolayers are often in deep, metastable states and respond to many thermodynamic stimuli. In fact, the structure of the monolayer is a metastable state governed by the statistical mechanics of the manifold of states existing for the 2-dimensional arrangement of the molecules and only weakly coupled-through a very large energy barrier-to states with a three-dimensional arrangement of the molecules. Therefore, the structure of surfactant monolayers on solid surfaces should be viewed through the models and theories describing the fundamental structure of interfacial phases. Unlike ...

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“…For example, in structure (6) with one ester group in the core and two alkoxy end groups, the melting point is raised by about 70 degrees and the transition to the smectic C* phase is raised by about 80 degrees. By incorporating a second ester function into the core of the molecule, (7), (8) the melting point can be lowered by 20 degrees. However, the smectic C* transition temperature drops by approximately 50 degrees.…”

Section: '-(2-methylbutyl)benzoate Esters Of the 4-n-alkoxybenzoatesmentioning

confidence: 99%

The ferroelectric phases derived from the 4-n-alkoxycinnamic acids

Leslie¹

1984

Ferroelectrics

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The optically active 4-(2-methylbutyloxy)phenol and 4-hydroxy-(2'-rnethylbutyl) benzoate esters of the p-n-alkoxycinnamic acids have been made and characterized. These materials show similar ferroelectric liquid crystal properties to and in a temperature range between those found for the analogous two and three benzene ring systems. These materials provide chiral smectic C phases in intermediate temperatures ranges (SO-90°C) required to produce eutectic ferroelectric mixtures over a wide range of temperatures.

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Structure and Correlations in Smectic B, F and I Phases

Cited by 120 publications

References 22 publications

Volume and X-ray diffraction study of terephthal-bis-4,n-decylaniline (TBDA)

Volume and X-ray diffraction study of terephthal-bis-4,n-decylaniline (TBDA)

Molecular structure of surfactant-coated surfaces

The ferroelectric phases derived from the 4-n-alkoxycinnamic acids

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