Séminaire

Mardi 22 Janvier 2019 à 11h00.

Far-from-equilibrium self assemblies: tunable structures in an electrically driven oil-in-oil system

''Self-assembly close to equilibrium is very well-studied, and yet many challenges remain in achieving controllable micro-scale structures. Increasingly it is realized that driven systems that are far from equilibrium, while far more difficult to have an intuition for, might yield surprises in the control of structures.
In a series of experiments [1-6], we have explored in depth a simple oil-in-oil emulsion where an external electric field can yield a rich variety of "tunability": i.e., frequency-controlled hydrodynamics, that yields different dynamical regimes and structures:
- from drop breakup to drop coalescence
- from crystals to disordered structures
- from 2D motions to convection to turbulence.
All are controlled by the super-diffusive motions of the underlying fluid (measured by tracer-particle flows).
[1] Varshney et al, Sci. Rep., 2012, 2, 738.
[2] Varshney et al, Lab Chip, 2014, 14, 1330.
[3] Varshney et al, Soft Matter, 2016, 12, 1759.
[4] Khajehpour Tadavani et al, Soft Matter, 2016, 12, 9246.
[5] Khajehpour Tadavani et al, Soft Matter, 2017, 13, 7412.
[6] Khajehpour Tadavani et al, Phys. Rev. E, 2018, 98, 022601.
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