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Microstructure, local dynamics, and flow behavior of colloidal suspensions with weak attractive interactions

Weis, C.; Oelschlaeger, C.; Dijkstra, D.; Ranft, M.; Willenbacher, N.

Abstract (englisch):
We present a comprehensive micro- and macrorheological study of the effect of weak depletion attraction (Ψdep ≈ 1–10 kBT) on dense colloidal suspensions stabilized by short-range repulsive interactions. We used aqueous polymer dispersions as model system and demonstrated the unique capabilities of multiple particle tracking (MPT) to disclose structural changes in such technically important systems exhibiting many characteristic features of hard sphere systems. Below the hard sphere freezing point ϕc, viscosity increases monotonically with increasing Ψdep due to the transition from a fluid to a fluid/crystalline and finally to a gel state. Above ϕc, increasing attraction strength first results in a viscosity reduction corresponding to the formation of large, permeable crystals and then in a viscosity increase when a network of dense, small crystals forms. The fraction of the fluid and crystal phase, particle concentration in each phase as well as the modulus of the micro-crystals are obtained, the latter decreases with Ψdep. Above the colloidal glass transition strong heterogeneities and different local particle mobility in the repul ... mehr


Zugehörige Institution(en) am KIT Institut für Mechanische Verfahrenstechnik und Mechanik (MVM)
Publikationstyp Zeitschriftenaufsatz
Jahr 2016
Sprache Englisch
Identifikator DOI: 10.1038/srep33498
ISSN: 2045-2322
URN: urn:nbn:de:swb:90-602763
KITopen ID: 1000060276
Erschienen in Scientific reports
Band 6
Seiten Art.Nr.:33498
Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds
Schlagworte Characterization and analytical techniques; Colloids; Glasses; Imaging techniques; Rheology
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