Bachelor Project
Dynamics of Droplet Phase Separation in Fluid Mixtures
Systems far from equilibrium are ubiquitous in nature and exhibit non-linear phase separation
dynamics as they approach equilibrium. Typical examples in daily life are coarsening of oil droplets
during salad dressing, rainfall, etc. When a homogeneous binary mixture (A+B) is rendered
thermodynamically unstable by a sudden temperature quench inside the co-existence curve, the
system phase separates into A-rich and B-rich domains. For a quench into the metastable region
of the co-existence curve, one observes droplet-like disconnected domains and phase ordering
progresses via the collision & coalescence of these droplets (see Figure). Recent studies [1,2]
revealed new insights into the nature of such droplet collisions – Brownian or deterministic, and
confirmed the droplet-growth law for a vapor–liquid system.
The aim of this project is to understand the nucleation, growth and motion of liquid droplets in a
binary fluid mixture in 3-d, via molecular dynamics simulations. Particular focus will be given on
quantifying the growth exponent, confirming the droplet growth law and investigating the presence
of inter-droplet interaction. In this connection, a comparison of the particle-diffusion mechanism
by Lifshitz-Slyozov and droplet-diffusion mechanism by Binder-Stauffer, in binary fluids, will also
be addressed.
1. S. Roy and S.K. Das, Soft Matter, 9, 4178 - 4187 (2013).
2. S.K. Das, S. Roy and J. Midya, Comptes Rendus Physique 16, 303-315 (2015).
Learning Content: Basics of non-equilibrium phase separation dynamics, Droplet coarsening
mechanisms in fluids, molecular dynamics simulation (overview).
Supervisor: Dr. Sutapa Roy
Max-Planck Institute for Intelligent Systems,
Heisenbergstrasse 3, 70569 Stuttgart.
Room No: 5E10
Email: [email protected]
URL: www.is.mpg.de/dietrich/roy
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