Phase separating colloid polymer mixtures in shear flow
| Autor: | Didi Derks, Arnout Imhof, Daniel Bonn, Dirk G. A. L. Aarts |
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| Přispěvatelé: | Soft Condensed Matter and Biophysics, Dep Natuurkunde, Soft Matter (WZI, IoP, FNWI) |
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Journal of physics. Condensed matter, 20. IOP PUBLISHING LTD Journal of Physics-Condensed Matter, 20(40). IOP Publishing Ltd. |
| ISSN: | 0953-8984 |
| DOI: | 10.1088/0953-8984/20/40/404208 |
| Popis: | We study the process of phase separation of colloid polymer mixtures in the (spinodal) two-phase region of the phase diagram in shear flow. We use a counter-rotating shear cell and image the system by means of confocal laser scanning microscopy. The system is quenched from an initially almost homogeneous state at very high ( 200 s(-1)) shear rate to a low shear rate (gamma)over dot. A spinodal decomposition pattern is observed. Initially, the characteristic length scale increases linearly with time. As the structure coarsens, the shear imposes a certain length scale on the structure and a clear asymmetry develops. The domains become highly stretched along the flow direction, and the domain width along the vorticity axis reaches a stationary size, which scales as approximate to(gamma)over dot(-0.35). Furthermore, on quenching from an intermediate (6.7 s(-1)) to a low shear rate the elongated structures become Rayleigh unstable and break up into smaller droplets. Still, the system eventually reaches the same steady state as was found from a direct high to low shear rate quench through coarsening. |
| Databáze: | OpenAIRE |
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