Dynamic correlation length in polymer solutions at the theta temperature

Résumé. 2014 Des mesures de sédimentation ont été effectuées dans une large gamme de concentration et de poids moléculaire sur des solutions de polystyrène-cyclohexane à 35,4 °C. L’utilisation d’une fraction de très haut poids moléculaire 20,6 x 106 nous a permis de dilater le régime semi-dilué vers les faibles concentrations. On en déduit que la longueur de corrélation dynamique 03BEH suit une loi d’échelle en concentration 03BEH ~ c-0,96 ± 0,04 en accord avec les prédictions théoriques. Abstract. 2014 Sedimentation velocity measurements have been performed in polystyrene-cyclohexane solutions at 35.4 °C. The use of extremely high molecular weight fractions, up to 20.6 x 106, has enabled us to study the concentration dependence of the dynamic correlation length in the semi-dilute regime. 03BEH scales as c- 0.96 ± 0.04 in agreement with theoretical predictions.

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