| dc.description.abstract | The shape transformations and composition variation of two-component model
lipid membrane isolated vesicles are studied. These are studied as aggregates in low
concentration solutions so that the vesicles are isolated from each other and interaction
effects can be ignored. The seminal work of Julicher and Lipowsky derived a curvaturefunctional
free energy, which has predicted or verified many of the experimentally
observed behaviors of model vesicles. One aspect that has not been well explored is the
composition variation of the liquid domains. In this work, the theory of Julicher and
Lipowsky is modified to include couplings between the curvature and composition but
the shape of the vesicle is restricted to include only ellipsoids of varying degree of
eccentricity and constant area. We also introduce a free energy to describe bilayered
micelles (“bicelles”). The energetics of this structure is studied and phase diagrams are
found for various vesicle-bicelle transitions. The properties of liquid domains, including
compositional variations with temperature are also discussed. These results are then
compared to experiments on vesicles and bicelles using small angle neutron scattering
and nuclear magnetic resonance. | |
