Related Experiment Video
Updated: May 23, 2026

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Molecular theory of the tilting transition in smectic liquid crystals with weak layer contraction and diffused cone
Mikhail Osipov1, Grzegorz Pająk
1Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, Richmond Street, Glasgow, Scotland, United Kingdom.
Abstract:
A molecular field theory of the smectic-A-smectic-C transition has been developed for smectics with a diffused cone orientational distribution of molecules (volcano-like distribution function) in the smectic-A phase and anomalously weak layer contraction in the smectic-C phase. Orientational order parameters and smectic layer spacing have been calculated numerically as functions of temperature and compared with the results obtained using a model with a standard Maier-Saupe-type distribution function that has been considered before. A molecular theory of the electroclinic effect in chiral smectics has also been developed using the recently proposed simple biaxial interaction potential. A comparison has been made between the absolute values and temperature variations of the electroclinic coefficient obtained using the volcano model, the model with Maier-Saupe-type distribution, and the orthodox cone model proposed by de Vries. It has been shown that the model with a conventional "sugar loaf" type orientational distribution function in the smectic-A phase is sufficient to describe the main properties of smectics with anomalously weak layer contraction.
Related Concept Videos
The Fluid Mosaic Model
MO Theory and Covalent Bonding
Theory of Strong Electrolytes
Molecular and Ionic Solids
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model

