(409g) Examining the Stability of Amphiphilic Janus Particle-Laden Interfaces

Recent advances in fabrication techniques have allowed for synthesis of anisotropic Janus particles. Studies of these particles have revealed multitude of exciting properties such as their ability to self-assemble and self-propel. Owing to their colloidal nature and amphiphilicity, Janus particles are believed to stabilize interfaces. Here, we explore the behavior of gold-capped silica Janus particles at the air-water and liquid-liquid interface. More specifically, the work investigates how the degree of amphiphilicity of gold-capped silica Janus particles affects their stability at the air-water interface. Amphiphilicity is varied by modification of the gold surface with alkane thiols of varying chain lengths. Stability of the particle-laden interface is studied under successive compressions and expansions of the air/water interface on a Langmuir trough. Samples of the interface are deposited on silicon wafers and examined using scanning electron microscopy to connect particle amphiphilicity, orientation at the interface, and stability of the monolayer under compression/expansion cycles. Additionally, internally fluorescent Janus particles have been synthesized for the first time to enable studies via confocal microscopy. In particular, this synthesis route is of interest for applications of Janus particles at liquid-liquid interfaces, such as in bijel synthesis.