Nematic Order Drives Phase Separation in Polydisperse Liquid Crystalline Polymers

2000 ◽  
Vol 33 (6) ◽  
pp. 2060-2068 ◽  
Author(s):  
F. Elias ◽  
S. M. Clarke ◽  
R. Peck ◽  
E. M. Terentjev
Keyword(s):  
Phase Separation ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Crystalline Polymers ◽  
Nematic Order

Liquid Crystal-Like Phase Separation in Systems of Macroscopic Rods

1988 ◽  
Vol 134 ◽  
Author(s):  
Larry A. Chick ◽  
Christopher Viney ◽  
Ilhan A. Aksay
Keyword(s):  
Phase Diagram ◽  
Liquid Crystal ◽  
Phase Separation ◽  
Liquid Crystalline ◽  
Axial Ratio ◽  
Liquid Crystalline Polymers ◽  
Two Dimensions ◽  
Crystalline Polymers ◽  
Critical Concentrations ◽  
Preliminary Phase

ABSTRACTExperiments with monolayers of macroscopic rods indicate separation into isotropic and aligned phases at greater-than-critical concentrations. This behavior is qualitatively similar to that of rodlike liquid crystalline polymers, which in turn has been modelled successfully in threedimensions by Flory and Ronca. We have adapted their approach to predict the ordering of rods in two dimensions. A preliminary phase diagram is presented. The critical rod concentration at which an aligned phase can appear first is a decreasing function of rod axial ratio. Rods of a given axial ratio will phase separate at lower overall concentrations in two dimensions than in three.

Phase Diagrams and Phase Separation Dynamics in Mixtures of Side-Chain Liquid Crystalline Polymers and Low Molar Mass Liquid Crystals

1996 ◽  
Vol 29 (3) ◽  
pp. 1051-1058 ◽  
Author(s):  
Hao-Wen Chiu ◽  
Zheng Long Zhou ◽  
Thein Kyu ◽  
Leonorina G. Cada ◽  
L.-C. Chien
Keyword(s):  
Phase Separation ◽  
Liquid Crystals ◽  
Phase Diagrams ◽  
Liquid Crystalline ◽  
Molar Mass ◽  
Liquid Crystalline Polymers ◽  
Side Chain ◽  
Crystalline Polymers

Influence of the nematic order on the rheology and conformation of stretched comb-like liquid crystalline polymers

2000 ◽  
Vol 1 (4) ◽  
pp. 301 ◽  
Author(s):  
V. Fourmaux-Demange ◽  
A. Brûlet ◽  
F. Boué ◽  
P. Davidson ◽  
P. Keller ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Crystalline Polymers ◽  
Nematic Order

Liquid crystalline polymers: self-organization and assembly

1993 ◽  
Vol 344 (1672) ◽  
pp. 403-417 ◽  
Keyword(s):  
Liquid Crystals ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Side Chain ◽  
Simple Liquid ◽  
Crystalline Polymers ◽  
Nematic Order ◽  
Nematic State ◽  
Chain Conformations

Liquid crystal forming monomers, typically rods, can be polymerized to form long mesogenic molecules. In contrast to simple rods, these polymers often have internal degrees of freedom so that they display the subtle behaviour of both high polymers and simple liquid crystals. They can have the rod elements either concatenated as a back-bone to give main chain (MC), or pendant to a back-bone to give side chain (SC) liquid crystals, or both. The physics unique to liquid crystalline polymers (LCPS) comes from their shape being dependent on the state of nematic order. Simple systems remain molecular rods (or disks) on ordering whereas a chain extends or flattens (depending on whether or not the nematic order is prolate or oblate). New phenomena as a result of this occur in situations as disparate as networks and, it is predicted, in dielectric response. We examine both SC and MC LCPS and the mechanisms by which they order lyotropically (in solution) and therm otropically (in the melt). Various types of models will be discussed in general and then restricted to the therm otropic case, lyotropic systems being discussed in Lekkerkerker & Vroege (this volume). The transition to the ordered state is first order as in simple nematics. The main characteristics of this state are modified chain conformations and, additionally for side chain polymers, transitions between various novel competing nematic states. A form of self-assembly that is a delicate function of the nematic order is observed in transesterifying LCPS. The number of chain ends is conserved but material exchanged between chains according to whether they are in the isotropic or nematic state. We review a model of this type of self-assembly.

Sign in / Sign up

Export Citation Format

Share Document