Direct observation of hydrodynamic instabilities in driven non-uniform colloidal dispersions
Abstract
A Rayleigh-Taylor-like instability of a dense colloidal layer under gravity in a capillary of microfluidic dimensions is considered. We access all relevant lengthscales with particle-level microscopy and computer simulations which incorporate long-range hydrodynamic interactions between the particles. By tuning the gravitational driving force, we reveal a mechanism whose growth is connected to the fluctuations of specific wavelengths, non-linear pattern formation and subsequent diffusion-dominated relaxation. Our linear stability theory captures the initial regime and thus predicts mixing conditions, with important implications for fields ranging from biology to nanotechnology.
Keywords
Cite
@article{arxiv.0810.1258,
title = {Direct observation of hydrodynamic instabilities in driven non-uniform colloidal dispersions},
author = {Adam Wysocki and C. Patrick Royall and Roland G. Winkler and Gerhard Gompper and Hajime Tanaka and Alfons van Blaaderen and Hartmut Löwen},
journal= {arXiv preprint arXiv:0810.1258},
year = {2008}
}
Comments
4 pages, 3 figures, submitted to Phys. Rev. Lett., movies available at http://www2.thphy.uni-duesseldorf.de/~adam/