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CANCELLED: CHBE 565 Seminar, Prof. Jian Qin, Stanford University (host: Prof. Charles Sing), "Effects of Polarity, Solvation, and Interfacial Polarization on Charge-Driven Assembly"

Event Type
Chemical and Biomolecular Engineering and International Paper Co.
116 Roger Adams Laboratory
Apr 23, 2020   2:00 pm  
Christy Bowser
Originating Calendar
Chemical & Biomolecular Engineering Seminars and Events

Screening of ionic interactions in dielectric medium is affected by polarizability, spatial variation of permittivity, and sharp dielectric boundary. Three examples are presented to illustrate the experimental consequence and theoretical rationale of these effects in self-assembled systems. The first example concerns the complexation of homologous polyelectrolytes in aqueous solution. Increasing monomeric polarity is shown to narrow the complexation window, which is fully accounted for by a molecule-inspired, statistical model. The second example concerns the morphology of ion-containing block polymers. We show that dielectric heterogeneity derived from morphological heterogeneity implies selective ionic solvation that rationalizes the experimental phase diagrams. The third example concerns the effective dielectric permittivity of particulate composites. We develop a generic dielectric virial expansion and show that interfacial polarization improves the classical Maxwell-Garnet model considerably.

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