TY  - JOUR
AU  - Squarcini, A.
AU  - Maciołek, A.
AU  - Eisenriegler, E.
AU  - Dietrich, S.
TI  - Critical Casimir interaction between colloidal Janus-type particles in two spatial dimensions
JO  - Journal of statistical mechanics: theory and experiment
VL  - 2020
IS  - 4
SN  - 1742-5468
CY  - Bristol
PB  - IOP Publ.
M1  - FZJ-2020-02074
SP  - 043208
PY  - 2020
AB  - We study colloidal particles with chemically inhomogeneous surfaces suspended in a critical binary liquid mixture. The inhomogeneous particle surface is composed of patches with alternating adsorption preferences for the two components of the binary solvent. By describing the binary liquid mixture at its consolute point in terms of the critical Ising model we exploit its conformal invariance in two spatial dimension. This allows us to determine exactly the universal profiles of the order parameter, the energy density, and the stress tensor as well as some of their correlation functions around a single particle for various shapes and configurations of the surface patches. The formalism encompasses several interesting configurations, including Janus particles of circular and needle shapes with dipolar symmetry and a circular particle with quadrupolar symmetry. From these single-particle properties we construct the so-called small particle operator expansion (SPOE), which enables us to obtain asymptotically exact expressions for the position- and orientation-dependent critical Casimir interactions of the particles with distant objects, such as another particle or the confining walls of a half plane, strip, or wedge, with various boundary conditions for the order parameter. In several cases we compare the interactions at large distances with the ones at close distance (but still large on the molecular scale). We also compare our analytical results for two Janus particles with recent simulation data.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000528535500001
DO  - DOI:10.1088/1742-5468/ab7658
UR  - https://juser.fz-juelich.de/record/877248
ER  -