Off-campus UMass Amherst users: To download campus access dissertations, please use the following link to log into our proxy server with your UMass Amherst user name and password.
Non-UMass Amherst users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
Dissertations that have an embargo placed on them will not be available to anyone until the embargo expires.
Title
Transitions Between Radial and Bipolar Liquid Crystal Drops in the Presence of Novel Surfactants
Author ORCID Identifier
https://orcid.org/0000-0002-0127-0569
AccessType
Open Access Dissertation
Document Type
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
Recommended Citation
Shechter, Jake, "Transitions Between Radial and Bipolar Liquid Crystal Drops in the Presence of Novel Surfactants" (2020). Doctoral Dissertations. 2079.
https://doi.org/10.7275/353g-a128
https://scholarworks.umass.edu/dissertations_2/2079