English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Accelerated Stokesian Dynamics (ASD) simulation and a microstructural theoryare applied to study structure and the viscosity of hard-sphere Browniansuspensions in active microrheology (MR).We consider moderate to densesuspensions, from near to far from equilibrium conditions.The theory explicitlyconsiders many-body hydrodynamic interactions (HIs) in active MR, and iscompared with ASD.Two conditions of moving the probe with constant force (CF)and constant velocity (CV) are considered.The structure is quantified using theprobability distribution of colloidal particles around the probe, g(r), whichis computed as a solution to the pair Smoluchowski equation (SE) for0.2<\phi<0.50, and a range of Peclet numbers (Pe), describing the ratio ofexternal force on the probe to thermal forces.Results of ASD and theorydemonstrate that a wake zone depleted of bath particles behind the moving probeforms at large Pe, while a boundary-layer accumulation develops upstream.Thewake length saturates at Pe>>1 for CF while it continuously grows in CV.Thiscontrast in behavior is related to the dispersion in the motion of the probeunder CF conditions, while CV motion has no dispersion.This effect isincorporated in the theory as a force-induced hydrodynamic diffusion flux inthe pair SE. We also demonstrate that, despite this difference of structure inCF and CV, g(r) near the probe is set by Pe, for both CF and CV resulting insimilar values for their viscosity.Using the theory, the structural anisotropyand Brownian viscosity near equilibrium are shown to be quantitatively similarin both CF and CV motions, which is in contrast with the dilute theory whichpredict distortions and Brownian viscosities twice as large in CV, relative toCF.This difference arises due to the many-body interactions associated with theequilibrium structure in the moderate to dense regime.

Active microrheology of colloidal suspensions: simulation and microstructural theory