Hydrodynamic interaction in quasi-two-dimensional suspensions

TL;DR

This paper investigates how confinement between two parallel surfaces significantly alters hydrodynamic interactions in quasi-two-dimensional colloidal suspensions, affecting their sign, decay, and concentration dependence, with experimental and theoretical insights.

Contribution

It provides new understanding of hydrodynamic interactions under confinement, showing that three-body effects do not influence large-distance coupling as previously expected.

Findings

Confinement changes the sign and decay of hydrodynamic coupling.

Three-body effects do not modify large-distance coupling.

Experimental and theoretical analysis confirms the altered interactions.

Abstract

Confinement between two parallel surfaces is found, theoretically and experimentally, to drastically affect the hydrodynamic interaction between colloid particles, changing the sign of the coupling, its decay with distance and its concentration dependence. In particular, we show that three-body effects do not modify the coupling at large distances as would be expected from hydrodynamic screening.