Flow induced crystallisation of penetrable particles

Abstract

For a system of Brownian particles interacting via a soft exponential potential we investigate the interaction between equilibrium crystallisation and spatially varying shear flow. For thermodynamic state points within the liquid part of the phase diagram, but close to the crystallisation phase boundary, we observe that imposing a Poiseuille flow can induce nonequilibrium crystalline ordering in regions of low shear gradient. The physical mechanism responsible for this phenomenon is shear-induced particle migration, which causes particles to drift preferentially towards the center of the flow channel, thus increasing the local density in the channel center. The method employed is classical dynamical density functional theory.

Self-assembly of binary solutions to complex structures

“…action between particles of species 1 bear such a feature and is modelled using the so-called generalised exponential model of order n (GEM-n) [48,49,[61][62][63][64][65][66][67][68][69]. In this work n = 4.…”

Self-assembly of binary solutions to complex structures

“…Such property implies a symmetry breaking, and thus the formation of periodic (or aperiodic) patterns. In the current work, the interaction between particles of species 1 bear such a feature and is modelled using the so-called generalised exponential model of order n (GEM-n) [48,49,[61][62][63][64][65][66][67][68][69].…”

Sensitive dependence on molecular interactions of length scales in sheared soft matter

“…is the flow kernel. This quantity has been introduced relatively recently, but its identification has already led to a series of advances in the areas of nonlinear rheology and colloidal fluids [50][51][52][53]57,58]. We venture to compare the current state-of-the-art knowledge of the flow kernel with the state of affairs when Ornstein and Zernike first identified the direct correlation function c (2) (r) in the early stages of equilibrium liquid state theory [56]: They knew it was important, but at first they knew very little about its full form.…”

“…However, forγ > 0 this is not necessarily the case. In the case of a system with one length scale, a sufficiently largeγ can result in ω > 0 for a small band of wave numbers at certain characteristic wave numbers, leading to a "laning instability" [50][51][52][53]57,58]. For systems with multiple intrinsic length scales, the dispersion relation exhibits several distinct peaks, each corresponding to a different length scale.…”

“…We suggest that this nonlinear behavior can be exploited to develop a class of active metadevices. The key conceptual step to perform this study is the identification of the shear kernel [50][51][52][53]57,58]. This only occurred recently and it deserves much future study.…”