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Ordering and self assembly in charged systems
We addressed the issue of ordering and self assembly in the context of flexible and semiflexible polyelectrolytes. The problems studied include the configurational and scattering properties of a single semiflexible polyelectrolyte in which we investigated the role of semiflexibility and electrostatics on the chain conformations. Effects of salt concentration and molecular weight have also been studied. Next, we extended the project to study orientational ordering induced by a collection of semiflexible polyelectrolytes with fixed molecular weight. We found rich phase behavior combining a first order Isotropic-Nematic phase transition and a second order critical point due to phase separation. Coupling of semiflexibility, electrostatics and their role on phase transition were investigated. Finally, we considered phase transitions in a solution of polydisperse semiflexible polymers, a problem which gives rise to interesting collective behavior. In the context of self assembly in charged system, we have also studied the process of micellization in a collection of polyelectrolytic diblock copolymers. The critical micelle concentration and its dependence on block molecular weights and salt concentration are discussed. Different problems have been studied with a combination of different analytical tools and numerical methods. The results of our research contrast with the existing literature and provide new insights in the field for future work. ^
Physics, Condensed Matter
"Ordering and self assembly in charged systems"
(January 1, 2003).
Electronic Doctoral Dissertations for UMass Amherst.