From nematic shells to nematic droplets: energetics and defect transitions

Area of Science:

• Soft Matter Physics
• Materials Science
• Chemical Engineering

Background:

• Liquid crystal shells with internal droplets exhibit complex behaviors.
• Osmotic pressure changes can alter droplet morphology and defect configurations.

Purpose of the Study:

• Investigate inducing valence transitions in nematic shells.
• Understand the transformation of nematic shells into nematic droplets.
• Analyze the factors governing defect reorganization versus inner droplet expulsion.

Main Methods:

• Numerical simulations of liquid crystal shell dynamics.
• Theoretical modeling of shell energy landscapes.
• Experimental observation of osmotic de-swelling processes.

Main Results:

• Observed two distinct pathways: defect reorganization or inner droplet expulsion.
• Demonstrated that the outcome depends on defect structure and system energetics.
• Identified osmotic pressure of the outer phase as a key factor influencing expulsion dynamics.

Conclusions:

• Valence transitions in nematic shells can be controlled by manipulating inner droplet size.
• The system's response is dictated by a balance between defect energy and droplet geometry.
• Fluid flow through the shell is implicated in the droplet expulsion mechanism.