Critical Casimir forces in colloidal suspensions on chemically patterned surfaces

TL;DR

This paper explores how critical Casimir forces influence colloidal particles near chemically patterned surfaces in a water-lutidine mixture, enabling tunable interactions and ordered monolayer formation.

Contribution

It demonstrates the tunability of critical Casimir forces on colloids near chemically patterned surfaces close to the mixture's critical point.

Findings

Critical Casimir forces can be tuned by surface properties and temperature.

These forces enable the formation of ordered colloidal monolayers.

The study extends understanding of colloid-surface interactions near criticality.

Abstract

We investigate the behavior of colloidal particles immersed in a binary liquid mixture of water and 2,6-lutidine in the presence of a chemically patterned substrate. Close to the critical point of the mixture, the particles are subjected to critical Casimir interactions with force components normal and parallel to the surface. Because the strength and sign of these interactions can be tuned by variations in the surface properties and the mixtures temperature, critical Casimir forces allow the formation of highly ordered monolayers but also extend the use of colloids as model systems.