Abstract

ABSTRACTLyotropic chromonic liquid crystals (LCLCs) are formed by linear stacks of disc-shaped molecular in water. Combined by weak, non-covalent forces, these aggregates are reversible, flexible and polydisperse. The self-assembly nature of the basic building units gives nematic LCLCs interesting physical properties, such as very small twist constant as compared with splay and bend constants, very large splay and twist viscosities, strong temperature dependence of , , and , diverse responses to different ionic additives, and large and azimuthally asymmetric disclination cores. We discuss our experimental studies on the viscoelastic properties and the fine structure of disclinations of LCLCs and attribute their unusual properties to the fact that LCLC aggregates are not fixed in size, but vary in response to changes of temperature, concentration and ionic content in the system. We further use these properties to explain intriguing phenomena in the ‘living liquid crystals’ composed of chromonic liquid crystal and motile bacteria Bacillus Subtilis.

Highlights

  • Lyotropic chromonic liquid crystals (LCLCs) are a new class of liquid crystal (LC) materials receiving increasing amount of interest in recent years [1,2,3,4,5]

  • We discuss our experimental studies on the viscoelastic properties and the fine structure of disclinations of LCLCs and attribute their unusual properties to the fact that LCLC aggregates are not fixed in size, but vary in response to changes of temperature, concentration and ionic content in the system

  • LCLC phases are sensitive to changes of temperature, concentration [2], ionic contents, pH, and crowding agents in the solution [8,9]

Read more

Summary

Introduction

Lyotropic chromonic liquid crystals (LCLCs) are a new class of liquid crystal (LC) materials receiving increasing amount of interest in recent years [1,2,3,4,5]. LCLC phases are sensitive to changes of temperature, concentration [2], ionic contents, pH, and crowding agents in the solution [8,9]. In the first section that follows, I will introduce our recent experimental studies on the temperature, concentration and ionic content dependences of the elastic constants and viscosity coefficients of LCLC materials. We explain our findings based on the model for lyotropic LCs composed of thin rods, which connects microscopic length and flexibility of the aggregates to the macroscopic elastic constants and viscosities of the system We supplement this model with the idea that LCLC aggregates are flexible and can change their length and flexibility in response to external stimuli. The two materials show some common features of the elastic constants: 2. Elasticity and viscosity of LCLCs

Temperature and concentration dependences of the elastic constants
Viscosities
Effect of ionic additives
Fine structures of topological defects: a study of disclinations in DSCG
Living liquid crystals
Findings
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call