Stability of Biaxial Nematic Phase for Systems with Variable Molecular Shape Anisotropy

Details Stability of Biaxial Nematic Phase for Systems with Variable Molecular Shape Anisotropy Stability of Biaxial Nematic Phase for Systems with Variable Molecular Shape Anisotropy

2007-03-28

arxiv.org/abs/cond-mat/0703736v2

Phys. Rev. E 76, 011703 (2007)

Physics

Condensed Matter

Soft Condensed Matter

18 pages containing 6 figures

Scientific paper

10.1103/PhysRevE.76.011703

We study the influence of fluctuations in molecular shape on the stability of the biaxial nematic phase by generalizing the mean field model of Mulder and Ruijgrok [Physica A {\bf 113}, 145 (1982)]. We limit ourselves to the case when the molecular shape anisotropy, represented by the alignment tensor, is a random variable of an annealed type. A prototype of such behavior can be found in lyotropic systems - a mixture of potassium laurate, 1-decanol, and $D_2O$, where distribution of the micellar shape adjusts to actual equilibrium conditions. Further examples of materials with the biaxial nematic phase, where molecular shape is subject to fluctuations, are thermotropic materials composed of flexible trimeric- or tetrapod-like molecular units. Our calculations show that the Gaussian equilibrium distribution of the variables describing molecular shape (dispersion force) anisotropy gives rise to new classes of the phase diagrams, absent in the original model. Depending on properties of the shape fluctuations, the stability of the biaxial nematic phase can be either enhanced or depressed, relative to the uniaxial nematic phases. In the former case the splitting of the Landau point into two triple points with a direct phase transition line from isotropic to biaxial phase is observed.

Affiliated with

Also associated with

No associations

Rating

Stability of Biaxial Nematic Phase for Systems with Variable Molecular Shape Anisotropy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Stability of Biaxial Nematic Phase for Systems with Variable Molecular Shape Anisotropy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stability of Biaxial Nematic Phase for Systems with Variable Molecular Shape Anisotropy will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-272138