Flow quantization and nonequilibrium nucleation of soft crystals

Author(s)
Arash Nikoubashman, Gerhard Kahl, Christos Likos
Abstract

We consider dense systems consisting of ultrasoft, overlapping particles under shear and transport flow, by employing a multiscale simulational approach that combines multiparticle-collision dynamics for the solvent particles with standard molecular dynamics for the solute. We find that the nucleation rates of supercooled liquids can be dramatically accelerated via the shear-induced formation of an intermediate string pattern, which disaggregates after the cessation of shear, leading to the emergence of three-dimensional fcc order. Furthermore we expose these cluster crystals to Poiseuille flow and we establish the emergence of a quantized flow pattern, in which both the height and the width of the fluid stream display well-defined plateaus as a function of the applied pressure gradient. The resulting velocity profiles of the solvent closely resemble plug flow. We explain the emergence of the plateaus by successive fluidization of crystalline layers adjacent to the channel walls and discuss the dependence of the discrete flow on the cluster aggregation parameter. Cluster crystals thus emerge as novel systems with applications on nano-and microfluidic devices, allowing the manipulation of flow in a precisely controlled way.

Organisation(s)
Computational and Soft Matter Physics
External organisation(s)
Technische Universität Wien
Journal
Soft Matter
Volume
8
Pages
4121-4131
No. of pages
11
ISSN
1744-683X
DOI
https://doi.org/10.1039/c1sm06899g
Publication date
2012
Peer reviewed
Yes
Austrian Fields of Science 2012
103023 Polymer physics, 103036 Theoretical physics, 103015 Condensed matter, 103029 Statistical physics
Portal url
https://ucrisportal.univie.ac.at/en/publications/21b9934d-9bba-4fcb-b5b1-53118d5ee887