skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Intrachain flexibility constraints on phase stabilities and odd-even effects in multiple smectic-A and nematic liquid crystals

Abstract

The importance of the flexibility of n-alkyl tail chains in real liquid-crystal systems is reviewed. Two new microscopic, molecular statistical-physics theories (a full statistical theory and a simpler but accurate approximate theory) for the intrachain constraints on the n-alkyl tail-chain flexibility are presented and are compared with each other and with an old, more approximate theory for tail-chain flexibility used in earlier papers. The new approximate approach is computationally much faster than the full statistical method and is the first treatment to generate and explain odd-even effects in multiple smectic-A phases and the first treatment to generate and explain odd-even effects in smectic-A and nematic phases without resorting to ad hoc or arbitrarily adjustable fits to experimental data. Phase stabilities and odd-even effects for various thermodynamic and molecular ordering properties are calculated in the smectic-A/sub 1/, smectic-A/sub d/, and nematic liquid-crystal phases and the isotropic liquid phase using the new approximate method. Some predictions and accompanying physical explanations are made for various systems that have not yet been chemically synthesized and/or experimentally studied.

Authors:
Publication Date:
Research Org.:
Theoretical Division, Los Alamos National Laboratory, University of California, Los Alamos, New Mexico 87545
OSTI Identifier:
7160890
Resource Type:
Journal Article
Journal Name:
Phys. Rev. A; (United States)
Additional Journal Information:
Journal Volume: 38:1
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; LIQUID CRYSTALS; FLEXIBILITY; ALKYL RADICALS; HYDROCARBONS; MOLECULAR STRUCTURE; ORDER PARAMETERS; ORIENTATION; PHASE STUDIES; CRYSTALS; FLUIDS; LIQUIDS; MECHANICAL PROPERTIES; ORGANIC COMPOUNDS; RADICALS; TENSILE PROPERTIES; 360602* - Other Materials- Structure & Phase Studies

Citation Formats

Dowell, F. Intrachain flexibility constraints on phase stabilities and odd-even effects in multiple smectic-A and nematic liquid crystals. United States: N. p., 1988. Web. doi:10.1103/PhysRevA.38.382.
Dowell, F. Intrachain flexibility constraints on phase stabilities and odd-even effects in multiple smectic-A and nematic liquid crystals. United States. https://doi.org/10.1103/PhysRevA.38.382
Dowell, F. 1988. "Intrachain flexibility constraints on phase stabilities and odd-even effects in multiple smectic-A and nematic liquid crystals". United States. https://doi.org/10.1103/PhysRevA.38.382.
@article{osti_7160890,
title = {Intrachain flexibility constraints on phase stabilities and odd-even effects in multiple smectic-A and nematic liquid crystals},
author = {Dowell, F},
abstractNote = {The importance of the flexibility of n-alkyl tail chains in real liquid-crystal systems is reviewed. Two new microscopic, molecular statistical-physics theories (a full statistical theory and a simpler but accurate approximate theory) for the intrachain constraints on the n-alkyl tail-chain flexibility are presented and are compared with each other and with an old, more approximate theory for tail-chain flexibility used in earlier papers. The new approximate approach is computationally much faster than the full statistical method and is the first treatment to generate and explain odd-even effects in multiple smectic-A phases and the first treatment to generate and explain odd-even effects in smectic-A and nematic phases without resorting to ad hoc or arbitrarily adjustable fits to experimental data. Phase stabilities and odd-even effects for various thermodynamic and molecular ordering properties are calculated in the smectic-A/sub 1/, smectic-A/sub d/, and nematic liquid-crystal phases and the isotropic liquid phase using the new approximate method. Some predictions and accompanying physical explanations are made for various systems that have not yet been chemically synthesized and/or experimentally studied.},
doi = {10.1103/PhysRevA.38.382},
url = {https://www.osti.gov/biblio/7160890}, journal = {Phys. Rev. A; (United States)},
number = ,
volume = 38:1,
place = {United States},
year = {1988},
month = {7}
}