Liquid crystal-carbon nanotubes mixtures.

Area of Science:

• Materials Science
• Soft Matter Physics
• Nanotechnology

Background:

• Nematic liquid crystals (LCs) exhibit self-organization, facilitating the alignment of dispersed carbon nanotubes (CNTs). Previous work focused on weak anchoring at the CNT-LC interface.
• Stronger anchoring conditions at the CNT-LC interface lead to distorted nematic ordering around the nanotubes, potentially creating significant long-range interactions.

Purpose of the Study:

• To theoretically investigate the alignment of carbon nanotubes (CNTs) in nematic liquid crystals (LCs) under strong anchoring conditions.
• To understand how the distorted LC ordering impacts the alignment and phase behavior of CNTs within the mixture.
• To explore the tunability of CNT ordering by adjusting system parameters like temperature and concentration.

Main Methods:

• Combined Landau-de Gennes free energy for LC ordering and Doi free energy for CNT ordering.
• Treated the LC and CNT components as a binary mixture, considering their mutual interactions.
• Analyzed the phase ordering as a function of CNT volume fraction, coupling strength, and temperature.

Main Results:

• Strong anchoring distorts the nematic ordering around CNTs, leading to anisotropic interactions.
• The degree of CNT ordering (nanorod alignment) is sensitive to temperature and CNT concentration.
• Phase ordering of the binary mixture can be controlled by varying temperature and CNT volume fraction.

Conclusions:

• The study provides a theoretical framework for understanding CNT alignment in LCs under strong anchoring.
• Tunable alignment of CNTs is achievable by manipulating temperature and concentration in LC-CNT mixtures.
• This work offers insights into designing materials with controlled anisotropic properties using self-organizing systems.