The electrophoretic separation of polyelectrolytes in dilute neutral polymer solutions are investigated through computer simulations and capillary electrophoresis experiments. The isolated entanglement dynamics of a mobile "probe" polyelectrolyte and "host" neutral polymer are simulated, using a Monte Carlo algorithm, providing insight into the effect of various probe and host parameters on molecular weight discrimination. Experiments employing narrow dispersity molecular weight fractions of pullulan as model most and poly(styrene sulfonate) as model probe, are used for investigation of bulk separation trends, in particular, to assess the role of host molecular weight. Both simulation and experiments indicate that probe separation in dilute matrices is dominated by the duration of probe/host entanglements. Single probe/host pairs alone are shown to impart a strong molecular weight discrimination, and this discrimination is highly affected by the size of the matrix polymer. A plot of probe mobility versus log of molecular weight is sigmoidal with the "best" separation occurring at comparable probe and host molecular weights. Probe separations are noted at concentrations as low as c*/8. A new understanding of the underlying molecular mechanisms of separation in dilute polymer solution matrices is achieved.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-3073 |
| Date | 01 January 1998 |
| Creators | Starkweather, Margaret Ellen |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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