Molecular orientational and dipolar correlation in the liquid crystal mixture E7: a molecular dynamics simulation...

Area of Science:

• Materials Science
• Computational Chemistry
• Condensed Matter Physics

Background:

• Nematic liquid crystals are crucial in display technologies.
• Understanding molecular ordering and dynamics in liquid crystal mixtures is essential for optimizing their performance.
• The commercial mixture E7 is widely used but its molecular-level behavior requires further investigation.

Purpose of the Study:

• To simulate the phase transition from isotropic liquid to nematic liquid crystal for the E7 mixture.
• To analyze the orientational and dipole order within the nematic phase of E7.
• To identify preferred molecular configurations and their impact on dipole correlations.

Main Methods:

• All-atom molecular dynamics simulations.
• 100 ns simulation time to observe phase growth.
• Analysis of orientational order parameters.
• Investigation of dipole-dipole correlations and molecular pair configurations.

Main Results:

• Direct observation of nematic phase growth from an isotropic liquid in 100 ns.
• The cyanoterphenyl component (5CT) exhibits higher molecular order than cyanobiphenyls.
• Both parallel and anti-parallel dipole correlations are present in E7.
• Strong anti-parallel dipole correlations are linked to specific molecular arrangements.
• Two preferred molecular pair configurations were identified, explaining the dipole correlation function g(1)(r).

Conclusions:

• Molecular dynamics simulations provide insights into the formation and behavior of the nematic liquid crystal E7.
• The study elucidates the role of molecular structure and arrangement in determining orientational and dipole order.
• Identified molecular configurations offer a basis for understanding and predicting the macroscopic properties of E7.