Bachelor of Philosophy Sample Thesis Prospectus

As new technologies are developed on the nano-to microscale, inspiration from biological systems often plays an important role. Recent advances allow the fabrication of vesicles from bilayer membranes, similar to cell membranes, of lipids or block copolymers. Multicomponent vesicles, containing more than one type of amphiphile, can phase separate into distinct domains. These domains have the ability to form buds, protruding from the extended membrane, in order to reduce their interfacial energy. In biological systems, such buds play a vital role in endo-and exocytosis and intracellular traffic. In soft nanotechnology, biomimetic budded vesicles will likewise have a vital role to play. Synthetic vesicles are already used for drug packaging and delivery and could potentially find application as robust nano-and microreactors and in such areas as pollution removal. Many of these potential applications of budded vesicles take place in driven flows. Analytic, numerical and experimental studies have shown that driven flows area capable of energetically facilitating shape transitions in single component vesicles. Other studies have demonstrated that the introduction of shear can significantly affect the interaction of a vesicle with a substrate. However, we know of no study that has examined how shear can affect a multicomponent budded vesicle. With the introduction of a second molecular species, we expect richer vesicle dynamics and phase behavior. Particularly, we anticipate that shear could facilitate topological transitions like bud pinch-off. Membrane behavior is a mesoscale phenomenon, occurring over length and time scales where traditional molecular dynamics is hindered by the large number of particles involved and the small time step necessitated by atomistic interaction potentials. However, molecular features are important at the mesoscale and should be retained in a useful simulation method. As a coarse grained simulation method with a soft interaction potential, dissipative particle dynamics (DPD) has opened new opportunities for numerical modeling. We use DPD to model the deformation of multicomponent budded vesicles in driven flow.