Berlin 2024 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 8: Polymer and Molecular Dynamics, Friction and Rheology

CPP 8.2: Vortrag

Montag, 18. März 2024, 15:15–15:30, H 0107

Fractional Viscoelastic Models for Describing Entangled Polymer Solutions — •Robert Franz Schmidt¹, Horst Henning Winter², and Michael Gradzielski¹ — ¹Stranski-Laboratorium, Institut für Chemie, TU Berlin, Berlin, Germany — ²Chemical Engineering and Polymer Science & Engineering, University of Massachusetts Amherst, Amherst, MA, USA

Soft matter materials frequently exhibit power-law viscoelastic responses due to a broad range of relaxation times. Classical viscoelastic models, based on series-parallel arrangements of springs and dashpots, predict exponential relaxation behavior and therefore have difficulty reproducing experimental data from power-law materials. Fractional viscoelastic models represent a second class of models that incorporate derivatives of fractional order in time.

We show that for poly(ethylene oxide) (PEO) solutions, the fractional Maxwell model (FMM) requires fewer model elements than classical spring-dashpot models for a reasonable description of the data and that it can be applied consistently to solutions with varying degrees of viscoelasticity. The fractional parameters exhibit scaling laws similar to classical parameters as a function of polymer concentration.

Keywords: rheology; fractional calculus; relaxation time spectrum; viscoelastic model