Rheology of suspensions stabilized by long grafted polymers

P.A. Nommensen, Michael H.G. Duits, J.S. Lopulissa, Henricus T.M. van den Ende, J. Mellema

Research output: Contribution to journalArticleAcademicpeer-review

20 Citations (Scopus)

Abstract

The synthesis of colloidal silica spheres grafted with long poly-(dimethyl siloxane) chains as described in literature has been successfully reproduced. The particles have been elaborately characterized, using different techniques and taking advantage of the availability of the unreacted bare particles and free polymer. Rheological measurements were performed on dispersions in heptane, all made from a single stock. An effective volume fraction was defined, based on the viscosity at low concentrations. Low shear viscosities and linear viscoelastic properties were measured at effective volume fractions up to 0.81. A transition from liquid-like to solid-like behavior is observed at φ ≅ 0.60. Up to this volume fraction, the particles behave much like Brownian hard spheres. At higher concentrations, softness effects become noticeable. Here, also differences from otherwise comparable soft spheres become pronounced.
Original languageUndefined
Pages (from-to)144-149
Number of pages6
JournalProgress in colloid and polymer science
Volume110
Issue number110]
DOIs
Publication statusPublished - 1998

Keywords

  • Dispersions - silica particle - polymer brush - characterization - rheology - hard spheres
  • METIS-129213
  • IR-73493

Cite this