Stability of smectic phases in hard-rod mixtures

Details Stability of smectic phases in hard-rod mixtures Stability of smectic phases in hard-rod mixtures

2005-09-08

arxiv.org/abs/cond-mat/0509216v1

J. Chem. Phys. 123, 104906 (2005).

Physics

Condensed Matter

Soft Condensed Matter

14 pages, 16 figures. To appear in JCP

Scientific paper

10.1063/1.2013251

Using density-functional theory, we have analyzed the phase behavior of binary mixtures of hard rods of different lengths and diameters. Previous studies have shown a strong tendency of smectic phases of these mixtures to segregate and, in some circumstances, to form microsegregated phases. Our focus in the present work is on the formation of columnar phases which some studies, under some approximations, have shown to become thermodynamically stable prior to crystallization. Specifically we focus on the relative stability between smectic and columnar phases, a question not fully addressed in previous work. Our analysis is based on two complementary perspectives: on the one hand, an extended Onsager theory, which includes the full orientational degrees of freedom but with spatial and orientational correlations being treated in an approximate manner; on the other hand, we formulate a Zwanzig approximation of fundamental-measure theory on hard parallelepipeds, whereby orientations are restricted to be only along three mutually orthogonal axes, but correlations are faithfully represented. In the latter case novel, complete phase diagrams containing regions of stability of liquid-crystalline phases are calculated. Our findings indicate that the restricted-orientation approximation enhances the stability of columnar phases so as to preempt smectic order completely while, in the framework of the extended Onsager model, with full orientational degrees of freedom taken into account, columnar phases may preempt a large region of smectic stability in some mixtures, but some smectic order still persists.

Affiliated with

Also associated with

No associations

Rating

Stability of smectic phases in hard-rod mixtures 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 smectic phases in hard-rod mixtures, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stability of smectic phases in hard-rod mixtures will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-2800