journal contributionposted on 30.07.2019, 00:00 by Adam W. Schuman
The assembly of immiscible liquid-liquid interfaces, like oil on water, is commonly found in biological, environmental, and industrial settings, but a relatively limited number of studies on this type of system have been conducted. In the UIC Physics Department, I have designed and constructed an in-house microscope to utilize the optical technique of Brewster angle microscopy to study temperature-controlled properties of liquid-liquid interfaces. In particular, we have observed the existence of a periodic, micron-sized structure in a state commonly referred to as a microphase for soluble surfactants near their transition temperatures. A likely cause for the stability of the microphase is due to competing intermolecular forces generated by the surfactant. In virtue of these forces, microphases develop near the vapor-solid transition temperature of the interfacial monolayer. The full range of this structure is observed as the temperature is incrementally stepped through the vapor-solid transition, including a microphase coexistence of clusters and stripes that form a seemingly endless labyrinth.