Fluidization and wall slip of soft-glassy materials by controlled surface roughness
Abstract
The motion of soft-glassy materials (SGM) in a confined geometry is strongly impacted by surface roughness. However, the effect of the spatial distribution of the roughness remains poorly understood from a more quantitative viewpoint. Here we present a comprehensive study of concentrated emulsions flowing in microfluidic channels, one wall of which is patterned with micron-size equally spaced grooves oriented perpendicularly to the flow direction. We show that roughness-induced fluidization can be quantitatively tailored by systematically changing both the width and separation of the grooves. We find that a simple scaling law describes such fluidization as a function of the density of grooves, suggesting common scenarios for droplet trapping and release. Numerical simulations confirm these views and are used to elucidate the relation between fluidization and the rate of plastic rearrangements.
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Cite
@article{arxiv.1611.01980,
title = {Fluidization and wall slip of soft-glassy materials by controlled surface roughness},
author = {Ladislav Derzsi and Daniele Filippi and Giampaolo Mistura and Matteo Pierno and Matteo Lulli and Mauro Sbragaglia and Massimo Bernaschi and Piotr Garstecki},
journal= {arXiv preprint arXiv:1611.01980},
year = {2017}
}
Comments
4 Figures. Supplementary Material. 2 Movies