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Author ORCID Identifier

https://orcid.org/0000-0002-0127-0569

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Degree Program

Physics

Year Degree Awarded

2020

Month Degree Awarded

September

First Advisor

Jennifer Ross

Second Advisor

Anthony Dinsmore

Third Advisor

S. Thayumanavan

Fourth Advisor

Christian Santangelo

Subject Categories

Condensed Matter Physics

Abstract

Liquid crystals (LCs) are a class of molecules that form a variety of configurations easily influenced by external interactions. Of particular interest are rod-like LC molecules confined to a spherical geometry, which have a competition between interfacial tension and elastic deformations. The configuration of the liquid crystal inside a droplet can be controlled using surfactants, influencing the boundary conditions, in an oil-in-water emulsion. I tested the effects of novel surfactants on the configuration of the LC droplets. These novel surfactant molecules, synthesized by collaborators, are oligomers with either a variable length hydrophobic domain or protein sensitive hydrophilic domain. I tested the equilibrium configuration and dynamics of configurational changes, comparing experimental results to simulations performed by collaborators. We find that configuration transitions can be triggered by the addition of a control surfactant, sodium dodecyl sulfate (SDS), but not the novel surfactants. The SDS concentration at which the phase transition occurs appears to depend on the droplet diameter and I observed a hysteresis in the SDS concentration of the phase transition, both of which depend on the novel surfactant present.

DOI

https://doi.org/10.7275/353g-a128

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