Novel starch microgels were prepared by emulsion cross-linking and characterized with respect to shape, volume, and mass density. Starch microgels appear to be negatively charged (similar to-50 mV), with a particle size varying as a function of the type of cross-linker (ca. 0.25-10 mum). Environmental scanning electron microscopy observations show a dependence of the particle swelling on the cross-linking density. Viscosimetry reveals that starch microgels behave as charged polymers, where the reduced viscosity increases with dilution (anomalous viscosity behavior) for sufficiently low kappaa (ca. kappaa < 3), the ratio of the particle radius (a), and the Debye length (kappa(-1)). Analogous results are obtained for reference-charged rigid silica spheres, which approach the hard sphere limit for increasing ionic strengths. The shape of the microgels appears to play a minor role in the anomalous viscosity behavior, which is more likely dominated by electrostatic effects. (C) 2002 Elsevier Science.
- Starch microgels
- Charged silica spheres
- Environmental scanning electron microscopy
- Ionic strength
- Intrinsic viscosity
- Starch colloids
Dziechciarek, Y., van Soest, J. J. G., & Philipse, A. P. (2002). Preparation and properties of starch-based colloidal microgels. Journal of Colloid and Interface Science, 246(1), 48-59. https://doi.org/10.1006/jcis.2001.8044