New Mechanism of Nonequilibrium Polymer Adsorption

Nonequilibrium states of surface composition can be extremely long-lived when polymer chains adsorb competitively. In a model system (polymethylmethacrylate adsorbed from CCl$_4$ onto oxidized silicon previously saturated with polystyrene), it is shown that a weakly adsorbing polymer was sterically...

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Veröffentlicht in:Science (American Association for the Advancement of Science) 1992-02, Vol.255 (5047), p.966-968
Hauptverfasser: Johnson, Harry E., Granick, Steve
Format: Artikel
Sprache:eng
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Zusammenfassung:Nonequilibrium states of surface composition can be extremely long-lived when polymer chains adsorb competitively. In a model system (polymethylmethacrylate adsorbed from CCl$_4$ onto oxidized silicon previously saturated with polystyrene), it is shown that a weakly adsorbing polymer was sterically pinned to a surface by a more strongly adsorbing polymer. The dynamical evolution of the surface composition was strongly nonexponential in time and non-Arrhenius in temperature; the phenomenology is analogous to bulk glasses. This interpretation offers a new mechanism to explain why weakly adsorbing chains may bind to surfaces, as well as a direction in which to look for a method to release them.
ISSN:0036-8075
1095-9203
DOI:10.1126/science.255.5047.966