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Crystals phases

A Shearographic Inspection System Using a Liquid Crystal Phase Modulator. [Pg.678]

We are all familiar with tire tliree states of matter gases, liquids and solids. In tire 19tli century the liquid crystal state was discovered [1 and 2] tliis can be considered as tire fourtli state of matter [3].The essential features and properties of liquid crystal phases and tlieir relation to molecular stmcture are discussed here. Liquid crystals are encountered in liquid crystal displays (LCDs) in digital watches and otlier electronic equipment. Such applications are also considered later in tliis section. Surfactants and lipids fonn various types of liquid crystal phase but this is discussed in section C2.3. This section focuses on low-molecular-weight liquid crystals, polymer liquid crystals being discussed in tire previous section. [Pg.2542]

The label liquid crystal seems to be a contradiction in tenns since a crystal cannot be liquid. However, tire tenn refers to a phase fonned between a crystal and a liquid, witli a degree of order intennediate between tire molecular disorder of a liquid and tire regular stmcture of a crystal. Wlrat we mean by order here needs to be defined carefully. The most important property of liquid crystal phases is tliat tire molecules have long-range orientational order. For tliis to be possible tire molecules must be anisotropic, whetlier tliis results from a rodlike or disclike shape. [Pg.2542]

Molecules tliat are capable of fonning liquid crystal phases are called mesogens and have properties tliat are mesogenic. From the same root, tire tenn mesophase can be used instead of liquid crystal phase. A substance in a liquid crystal phase is tenned a liquid crystal. These conventions follow tliose in tire Handbook of Liquid Crystals, [4, 5 and 6] tire nomenclature of which [7] for various liquid crystal phases is adopted elsewhere in tliis section. [Pg.2542]

Liquid crystal phases can be divided into two classes. Thermotropic liquid crystal phases are fonned by pure... [Pg.2542]

Thennotropic liquid crystal phases are fonned by anisotropic molecules witli long-range orientational order and in many types of stmcture witli some degree of translational order. The main types of mesogen are Arose tlrat are rodlike or calamitic and Arose Arat are disclike or discotic. [Pg.2543]

Figure C2.2.7. Schematic illustrating tire classification and nomenclature of discotic liquid crystal phases. For tire columnar phases, tire subscripts are usually used in combination witli each otlier. For example, denotes a rectangular lattice of columns in which tire molecules are stacked in a disordered manner (after [33])... Figure C2.2.7. Schematic illustrating tire classification and nomenclature of discotic liquid crystal phases. For tire columnar phases, tire subscripts are usually used in combination witli each otlier. For example, denotes a rectangular lattice of columns in which tire molecules are stacked in a disordered manner (after [33])...
Liquid crystal phases possess characteristic textures when viewed in polarized light under a microscope. These textures, which can often be used to identify phases, result from defects in tire stmcture. Compendia of micrographs showing typical textures exist to facilitate phase identifications [37, 38]. These monographs also discuss tire origins of defect stmctures in some detail. [Pg.2551]

As in crystals, defects in liquid crystals can be classified as point, line or wall defects. Dislocations are a feature of liquid crystal phases where tliere is translational order, since tliese are line defects in tliis lattice order. Unlike crystals, tliere is a type of line defect unique to liquid crystals tenned disclination [39]. A disclination is a discontinuity of orientation of tire director field. [Pg.2551]

X-ray diffraction is one of the primary methods to detennine the stmcture of a liquid crystal phase [22, 51]. [Pg.2553]

This method is used to locate phase transitions via measurements of the endothennic enthalpy of phase transition. Details of the teclmique are provided elsewhere [25, 58]. Typically, the enthalpy change associated with transitions between liquid crystal phases or from a liquid crystal phase to the isotropic phase is much smaller than the melting enthalpy. Nevertheless, it is possible to locate such transitions with a commercial DSC, since typical enthalpies are... [Pg.2554]

Thennotropic liquid crystal phases are fonned by rodlike or disclike molecules. However, in the following we consider orientational ordering of rodlike molecules for definiteness, although the same parameters can be used for discotics. In a liquid crystal phase, the anisotropic molecules tend to point along the same direction. This is known as the director, which is a unit vector denoted n. [Pg.2554]

Typical shapes of the orientation distribution function are shown in figure C2.2.10. In a liquid crystal phase, the more highly oriented the phase, the moreyp tends to be sharjDly peaked near p=0. However, in the isotropic phase, a molecule has an equal probability of taking on any orientation and then/P is constant. [Pg.2555]

An orientational order parameter can be defined in tenns of an ensemble average of a suitable orthogonal polynomial. In liquid crystal phases with a mirror plane of symmetry nonnal to the director, orientational ordering is specified. [Pg.2555]

Figure C2.2.10. Orientational distribution functions for (a) a highly oriented liquid crystal phase, (b) a less well... Figure C2.2.10. Orientational distribution functions for (a) a highly oriented liquid crystal phase, (b) a less well...
McMillan s model [71] for transitions to and from tlie SmA phase (section C2.2.3.2) has been extended to columnar liquid crystal phases fonned by discotic molecules [36, 103]. An order parameter tliat couples translational order to orientational order is again added into a modified Maier-Saupe tlieory, tliat provides tlie orientational order parameter. The coupling order parameter allows for tlie two-dimensional symmetry of tlie columnar phase. This tlieory is able to account for stable isotropic, discotic nematic and hexagonal columnar phases. [Pg.2560]

Pershan P S 1988 Structure of Liquid Crystal Phases (Singapore World Soientifio)... [Pg.2566]

Frenkel D 1992 Computer simulations of phase transitions in liquid crystals Phase Transitions in Liquid Crystals ed S Martellucci and A N Chester (New York Plenum)... [Pg.2569]

In practice, colloidal systems do not always reach tlie predicted equilibrium state, which is observed here for tlie case of narrow attractions. On increasing tlie polymer concentration, a fluid-crystal phase separation may be induced, but at higher concentration crystallization is arrested and amorjihous gels have been found to fonn instead [101, 102]. Close to the phase boundary, transient gels were observed, in which phase separation proceeded after a lag time. [Pg.2688]

Kitakami O et al 997 Size effect on the crystal phase of cobalt fine particles Phys. Rev. B 56 13 849 Cullity B D 1978 Elements of X-ray Diffraction (Reading, MA Addison-Wesley)... [Pg.2920]

Fig. 22. Effects of polyphosphate level and N P20 weight ratio on solubility of ammoniated phosphoric acids at 0°C, where A represents 70% of total P20 as polyphosphate B, 45% and C, 0%, and the various crystallizing phases are (1), (NH H2PO (2), (NH 2HPO (3), (NH g HEgO -HgO) (4),... Fig. 22. Effects of polyphosphate level and N P20 weight ratio on solubility of ammoniated phosphoric acids at 0°C, where A represents 70% of total P20 as polyphosphate B, 45% and C, 0%, and the various crystallizing phases are (1), (NH H2PO (2), (NH 2HPO (3), (NH g HEgO -HgO) (4),...
Crystal phase is P-quartz ZrTiO unless otherwise noted. Corning. [Pg.324]


See other pages where Crystals phases is mentioned: [Pg.678]    [Pg.685]    [Pg.341]    [Pg.2279]    [Pg.2543]    [Pg.2543]    [Pg.2543]    [Pg.2549]    [Pg.2551]    [Pg.2551]    [Pg.2553]    [Pg.2554]    [Pg.2554]    [Pg.2554]    [Pg.2556]    [Pg.2564]    [Pg.2668]    [Pg.2688]    [Pg.182]    [Pg.609]    [Pg.686]    [Pg.1057]    [Pg.467]    [Pg.226]    [Pg.290]    [Pg.319]    [Pg.320]    [Pg.321]    [Pg.322]   
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A-crystal phase

Accelerated Crystal Nucleation in the Concentrated Phase

Anatase, crystal phases

And crystal phases

Application of Phase Diagrams in Co-crystal Search and Preparation

Applying Phase Diagrams to Single-Crystal Growth

Atactic crystal phase

Atomic diffusion in crystallized phases

Banana phases achiral liquid crystals

Bicontinuous phases liquid crystals

Blue Phases of Chiral Liquid Crystals

Bonding, Crystal Structure, and Phase Stability

Bowlic liquid crystal phase

Calamitic liquid crystal phases

Celsian crystal phases

Characteristics of Liquid Crystal Phases

Chiral crystals, phase behavior

Cholesteric gels liquid crystal phase

Cholesteric liquid crystal phases

Cholesteric liquid crystal polymer phase

Cholesteric phase, thermotropic liquid crystals

Columnar discotic liquid crystal phase

Columnar phases, thermotropic liquid crystals

Comments on the crystal structures of typical hydrogen-metal phases

Condensed crystal phases

Confinement liquid crystals, nematic phase

Confinement liquid crystals, smectic phase

Crystal Laves phases

Crystal Phases of Polymers

Crystal Structure of Phases

Crystal bulk phase

Crystal crystalline phase

Crystal data and X-ray powder patterns for ferrite phase containing foreign ions

Crystal formation metastable phases

Crystal formation phase diagram

Crystal growth and phase transformations

Crystal growth metastable phases

Crystal phase measurements

Crystal phase order parameter

Crystal phase relaxations

Crystal phase separation

Crystal phase transitions

Crystal phase volume

Crystal phases determination

Crystal smectic phases

Crystal structure and phase stability

Crystal structure and phase transitions

Crystal structure elements, phase transitions

Crystal structures, polymers amorphous phase

Crystal structures, polymers crystalline phase

Crystal-phase photochemical reactions

Crystallity phase relationship

Crystallization from a Vapor Phase, Sublimation and Desublimation

Crystallization from a single-phase mixture

Crystallization of the sulphate phases

Crystallization phase diagrams

Crystallization phase space

Crystallization phase transitions during

Crystallization resolution phase diagrams

Crystallization, metastable phases

Crystallization-Induced Vertical Phase Segregation

Crystals phase problem with

Crystals phase transformations

Cubic liquid crystal phases

Cubic lyotropic liquid crystal phases

Daughter crystals/phases

Determination of Crystal Phases

Discotic liquid crystal phases

Discotic liquid crystals phase transition temperatures

Dispersed phases fractionated crystallization during

Dynamic Scattering in SmA Liquid Crystal Phases

Elastic behavior liquid crystals, nematic phase

Electro-Optical Effects in Other Phases of Liquid Crystals

Electronic materials—phase diagram and crystal growth of GaAs

Elements crystal phase transitions

Fluctuations and Liquid Crystal Phase Transitions

Formation of the liquid crystal phase

Frustrated smectic liquid crystal phases

Gel-liquid crystal phase transition

Gelation Crystallization Phase

Grain crystal phase

Hexagonal lyotropic liquid crystal phases

Hexagonal structures liquid crystal phases

Hybrid crystals, single phase

Identification of liquid crystal phases

Identification of liquid crystal phases—mesophase characterisation

Initiation of Crystallization - Nucleation Phase

Isotropic phases, liquid crystal-supercooled

Isotropic-nematic phase transition thermotropic liquid crystals

Lamellar liquid crystal phase spectrum

Lamellar liquid crystal phases

Lamellar lyotropic liquid crystal phases

Laves phase compounds crystal field

Liquid Crystal Honeycombs and Other Complex Phase Structures of T-Shaped Ternary Amphiphiles

Liquid Crystal Phases at High Concentrations

Liquid crystal materials lyotropic nematic phases

Liquid crystal materials nematic phases

Liquid crystal materials other lyotropic phases

Liquid crystal materials smectic phases

Liquid crystal phase

Liquid crystal phase applications

Liquid crystal phase common molecular features

Liquid crystal phase computer simulations

Liquid crystal phase definition

Liquid crystal phase molecular structure effects

Liquid crystal phase stability

Liquid crystal phase structure visualization

Liquid crystal phases, characterization

Liquid crystal phases, nanoparticle-doped

Liquid crystal polymers phases

Liquid crystals A phase

Liquid crystals Middle phase

Liquid crystals SmCP phases

Liquid crystals blue phase

Liquid crystals calamitic mesogen phases

Liquid crystals chiral phases

Liquid crystals columnar phases

Liquid crystals crystal phases

Liquid crystals discotic mesogen phases

Liquid crystals isotropic phase

Liquid crystals mesogenic compounds, phase transitions

Liquid crystals nematic phase

Liquid crystals nematic phase elastic properties

Liquid crystals phase behaviour

Liquid crystals phase changes

Liquid crystals phase transitions

Liquid crystals reverse hexagonal phase

Liquid crystals smectic phase

Liquid crystals under pressure, phase diagrams

Liquid(Solution)-Crystal Phase Separation

Liquid-crystal discontinuous cubic phase

Liquid-crystal hexagonal phase

Liquid-phase precipitation crystal shape

Lyotropic liquid crystal phases

Lyotropic liquid crystals phase diagrams

Lyotropic liquid crystals phase sequence

Making Crystals by Phase Transition

Melt crystallization phase diagrams

Metals crystal phase transitions

Metastable crystal phases

Models liquid crystal cubic phase

Molecular crystal substrates crystalline phases

Nematic liquid crystal phase characteristics

Nematic liquid crystal phase distributions/order

Nematic liquid crystal phase molecular arrangements

Nematic liquid crystal phase molecular features

Nematic liquid crystal phase stability

Nepheline crystal phases

Paraelectric phase, ferroelectric crystals

Phase Biaxiality in Nematic Liquid Crystals

Phase Diagram for Side Group Liquid Crystal - Coil Systems

Phase Diagrams for Crystal Growth

Phase Diagrams for Most Efficient Co-crystal Search

Phase Diagrams vs. Crystal Growth from Liquid Phases

Phase Equilibria and Growth of Langasite-Type Crystals

Phase Structures of Calamitic Liquid Crystals

Phase Transitions in Rod-Like Liquid Crystals

Phase behaviour of lyotropic side chain polymer liquid crystals

Phase clusters, crystallization

Phase crystal structure problem

Phase diagram and crystal structures

Phase diagrams of pure polymer liquid crystals

Phase diagrams, crystallization-based

Phase diagrams, crystallization-based solubility

Phase equilibrium and crystal

Phase equilibrium and crystal structure

Phase equilibrium crystal-liquid

Phase of Liquid Crystals

Phase plastic crystal

Phase refinement virus crystals

Phase separation and crystallization

Phase separation crystallization techniques

Phase separation photonic crystals

Phase transformation crystal-liquid

Phase transition and crystal structure of zirconia

Phase transition behavior, liquid crystal ionic

Phase transition dynamics thermotropic liquid crystals

Phase transition, ferroelectric crystals

Phase transitions ammonium triiodate crystal model

Phase transitions in liquid crystals

Phase transitions polymers, glass to crystal

Phases and crystal structure

Phases ferroelectric liquid crystal

Photochemical crystal phase

Plastic crystal crystalline phase structure

Pollmann 3 Fluctuations and Liquid Crystal Phase Transitions

Poly stress-induced crystal phase

Polymer blend phase behavior crystal

Polymer liquid crystals nematic phases

Polymer liquid crystals smectic phases

Polymer network stabilized liquid crystal phase

Polymer-Stabilized Blue Phase Liquid Crystals

Protein crystallization phase diagrams

Proteins liquid crystal phases

Pyrazine crystal phases

Re-entrant Phase Transitions in Liquid Crystals

Reversed hexagonal lyotropic liquid crystal phases

Reversed phases liquid crystals

Rod-Like Liquid Crystals Combining RH- and RF-Chains Monolayer Smectic Phases

Rotational Diffusion of Liquid Crystals in the Nematic Phase

Scattering in the Isotropic Phase of Liquid Crystals

Secondary crystal phase

Single Crystal and Gas Phase Raman Spectroscopy in Inorganic Chemistry

Single-crystal phase transition studie

Single-crystal phase transition studie motions

Single-crystal structure analyses phases

Single-phase alloys crystal structures

Smectic phases thermotropic liquid crystals

Smectic phases, liquid crystal ionic liquids

Solid intermetallic phases crystal structure

Solid phase crystallization method

Solid-liquid crystal phase transition

Solid-phase crystallization

Solid-phase crystallization technique

Solution-phase synthesis crystallizations

Spinel glass-ceramics crystal phases

Sponge phases liquid crystals

Stationary phases liquid crystal

Structural analysis crystal-phase structures

Structural liquid crystal phases

Structure of Liquid Crystal Phases

Structure of the Crystal B Phase

Structures of the Crystal J and G Phases

Subject crystal phase transformation

Symmetry Relations at Phase Transitions. Twinned Crystals

Syndiotactic crystal phase

Tailoring Co-crystal Solubility via Solution Phase Chemistry

The Prototype Phase Change Material Ge2Sb2Te5 Amorphous Structure and Crystallization

The Structure of Liquid Crystal Phases

Thermodynamic Properties of Liquid Crystal Phase Transitions

Thermotropic liquid crystal phases

Thermotropic liquid crystals chiral nematic phase

Thermotropic liquid crystals crystal smectic phases

Thermotropic liquid crystals nematic phase

Viruses liquid crystal phases

Water, crystal structure equilibrium between phases

Wide Angle Scattering During Crystallization and Solid State Phase Transitions

Y-phase crystal

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