Divergent Shear Thinning and Shear Thickening Behavior of Supramolecular Polymer Networks in Semidilute Entangled Polymer Solutions.

Published

Journal Article

The steady shear behavior of metallo-supramolecular polymer networks formed by bis-Pd(II) cross-linkers and semidilute entangled solutions of poly(4-vinylpyridine) (PVP) in dimethyl sulfoxide (DMSO) or N,N-dimethyl formamide (DMF) is reported. The steady shear behavior of the networks depends on the dissociation rate and association rate of the cross-linkers, the concentration of cross-linkers, and the concentration of the polymer solution. The divergent steady shear behavior-shear thinning versus shear thickening-of samples with identical structure but different cross-linker dynamics (J. Phys. Chem. Lett. 2010, 1, 1683-1686) is further explored in this paper. The divergent steady shear behavior for networks with different cross-linkers is connected to a competition between different time scales: the average time that a cross-linker remains open (τ(1)) and the local relaxation time of a segment of polymer chain (τ(segment)). When τ(1) is larger than τ(segment), shear thickening is observed. When τ(1) is smaller than τ(segment), only shear thinning is observed.

Full Text

Duke Authors

Cited Authors

  • Xu, D; Liu, C-Y; Craig, SL

Published Date

  • January 2011

Published In

Volume / Issue

  • 44 / 7

Start / End Page

  • 2343 - 2353

PubMed ID

  • 21547008

Pubmed Central ID

  • 21547008

Electronic International Standard Serial Number (EISSN)

  • 1520-5835

International Standard Serial Number (ISSN)

  • 0024-9297

Digital Object Identifier (DOI)

  • 10.1021/ma2000916

Language

  • eng