Phase transitions of liquid crystal PAA in confined geometries
Article Abstract:
An investigation of phase transitions of liquid crystal PAA, p-azoxyanisole, in porous sol-gels of average pore diameters 8.9, 16 and 20 nm, revealed that the phase transition temperatures inside small pores are depressed, with depressions depending on the pore size. Using Raman spectroscopy and differential scanning calorimetry, this was observed for the solid to nematic and the nematic to isotropic phase transitions of PAA. Such phase behavior cannot be modified by surface modifications wherein -OH groups are replaced by -Si(CH)3 groups. The size of the crystal is limited by the restricted space, which dominates the phase transitions.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
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Lyotropic system potassium laureate/1-decanol/water as a carrier medium for a ferronematic liquid crystal: phase diagram study
Article Abstract:
A synthetic approach to lyotropic mixtures of potassium laureate, 1-decanol and water is described and the components of the ternary system prior to mixing, the way of mixing and the lyotropic compositions themselves characterized. A number of states are identified, including an isotropic phase, a nematic phase, a very viscous phase, an ordered phase that is extremely viscous and a diphasic domain located between the isotropic and nematic regions.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
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Decanol effect on the structure of the hexagonal phase in a lyotropic liquid crystal
Article Abstract:
Issues concerning the structure of the hexagonal phase of the ternary system for a fixed water:sodium dodecyl (lauryl) sulfate molar ratio of 39.4 are discussed. It is possible to confirm a crossover from the finite/rigid model to the infinite/flexible model for the hexagonal phase with a rise in the decanol content.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2000
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