Journal of the American Chemical Society · 2013 · 106 citations · 32 references
Natural SciencesChemistryMaterials SciencePolymer ChemistrySurface ChemistrySurface ScienceAdsorption At InterfacesPolymer AdhesionPolymer PhysicsPolymer Thin FilmsSurface DiffusionSurface ImmobilizationDesorptionMolecular Dynamics Of Surface DiffusionPolymer AdsorptionPolymer Conformation In Thin FilmsPolymer DiffusionPolymer Surface ChemistrySolid-liquid Interface DynamicsSolid-liquid Interface Motion
The dynamics of polymers adsorbed to a solid surface are important in thin-film formation, adhesion phenomena, and biosensing applications, but they are still poorly understood. Here we present tracking data that follow the dynamics of isolated poly(ethylene glycol) chains adsorbed at a hydrophobic solid-liquid interface. We found that molecules moved on the surface via a continuous-time random walk mechanism, where periods of immobilization were punctuated by desorption-mediated jumps. The dependence of the surface mobility on molecular weight (2, 5, 10, 20, and 40 kg/mol were investigated) suggested that surface-adsorbed polymers maintained effectively three-dimensional surface conformations. These results indicate that polymer surface diffusion, rather than occurring in the two dimensions of the interface, is dominated by a three-dimensional mechanism that leads to large surface displacements and significant bulk-surface coupling.
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The nonlinear nature of friction
Michael Urbakh, J. Klafter, Delphine Gourdon et al. · Nature · 2004 · 690 citations