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DOE OSTI · 1773872

Polyelectrolyte Surface Diffusion in a Nanoslit Geometry

Morrin, Gregory T.·Kienle, Daniel F.·Weltz, James S.·Traeger, Jeremiah C.·Schwartz, Daniel K.
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Abstract

The surface diffusion of poly-l-lysine (PLL) in a planar nanoslit was studied using convex lens-induced confinement (CLiC) single-molecule tracking microscopy. Here, three surface chemistries were employed to understand the interplay of electrostatic and short-range interactions: an amine-functionalized silica surface, an oligo(ethylene oxide) (OEG)-modified surface, and a 1:1 mixture of the two ligands. Effective surface diffusion coefficients increased rapidly with slit height until saturating for slit heights <30 nm. While diffusion at a semi-infinite interface was significantly faster for OEG surfaces, the diffusion coefficient increased most rapidly with slit height for amine-functionalized surfaces, resulting in surface diffusion within very thin slits being nearly independent of surface chemistry. Intermittent random walks were simulated within a planar slit geometry, using experimentally measured parameters obtained from diffusion at a single interface to account for the characteristic short-range interactions between PLL and each surface chemistry, and were in good agreement with experimental measurements.

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Morrin, Gregory T., Kienle, Daniel F., Weltz, James S., Traeger, Jeremiah C., Schwartz, Daniel K.. 2020-05-13. Polyelectrolyte Surface Diffusion in a Nanoslit Geometry. https://doi.org/10.1021/acs.macromol.9b02365

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