Depinning and heterogeneous dynamics of colloidal crystal layers under shear flow
arXiv:1608.07419 · doi:10.1103/PhysRevE.94.062605
Abstract
Using Brownian dynamics (BD) simulations and an analytical approach we investigate the shear-induced, nonequilibrium dynamics of dense colloidal suspensions confined to a narrow slit-pore. Focusing on situations where the colloids arrange in well-defined layers with solidlike in-plane structure, the confined films display complex, nonlinear behavior such as collective depinning and local transport via density excitations. These phenomena are reminiscent of colloidal monolayers driven over a periodic substrate potential. In order to deepen this connection, we present an effective model which maps the dynamics of the shear-driven colloidal layers to the motion of a single particle driven over an effective substrate potential. This model allows to estimate the critical shear rate of the depinning transition based on the equilibrium configuration, revealing the impact of important parameters such as the slit-pore width and the interaction strength. We then turn to heterogeneous systems where a layer of small colloids is sheared with respect to bottom layers of large particles. For these incommensurate systems we find that the particle transport is dominated by density excitations resembling the so-called "kink" solutions of the Frenkel-Kontorova (FK) model. In contrast to the FK model, however, the corresponding "antikinks" do not move.
References in corpus (18)
- Modeling friction: From nanoscale to mesoscale
- Nonequilibrium equation of state in suspensions of active colloids
- Static and dynamic friction in sliding colloidal monolayers
- Effect of controlled corrugation on capillary condensation of colloid-polymer mixtures
- Onset of flow in a confined colloidal glass under an imposed shear stress
- Binary crystals in two-dimensional two-component Yukawa mixtures
- Rheology of confined non-Brownian suspensions
- Dynamic Regimes for Driven Colloidal Particles on a Periodic Substrate at Commensurate and Incommensurate Fillings
- Transmission of torque at the nanoscale
- Crystallization in a sheared colloidal suspension
- Nonlinear Driven Response of a Phase-Field Crystal in a Periodic Pinning Potential
- Confined colloidal crystals in and out of equilibrium
- On the waiting time distribution for continuous stochastic systems
- Reentrant Network Formation in Patchy Colloidal Mixtures under Gravity
- Surface-charge-induced freezing of colloidal suspensions
- Non-equilibrium dynamics of a confined colloidal bilayer in planar shear flow
- How does a thermal binary crystal break under shear?
- The Anatomy of Plastic Events in Magnetic Amorphous Solids