Phase Transitions in Two-Dimensional Systems of Janus-like Particles on a Triangular Lattice.

Andrzej Patrykiejew

doi:10.3390/ijms221910484

Abstract

We studied the phase behavior of two-dimensional systems of Janus-like particles on a triangular lattice using Monte Carlo methods. The model assumes that each particle can take on one of the six orientations with respect to the lattice, and the interactions between neighboring particles were weighted depending on the degree to which their A and B halves overlap. In this work, we assumed that the AA interaction was fixed and attractive, while the AB and BB interactions varied. We demonstrated that the phase behavior of the systems considered strongly depended on the magnitude of the interaction energies between the AB and BB halves. Here, we considered systems with non-repulsive interactions only and determined phase diagrams for several systems. We demonstrated that the phase diagram topology depends on the temperature at which the close-packed systems undergo the orientational order–disorder transition.

Highlights

Janus particles have a surface composed of two chemically different patches, A andB [1,2]
In our recent paper [13], we studied the orientational order–disorder transitions in closely packed two-dimensional systems of Janus particles, using a simple lattice model, which allowed for only six different orientations of each particle
We studied the phase behavior of two-dimensional systems of Janus-like particles on a triangular lattice

Summary

Introduction

Janus particles have a surface composed of two chemically different patches, A andB [1,2]. The chemical composition and the size of patches, influence both self-assembly and the formation of different ordered structures in two- and three-dimensional systems [3,4,5,6,7,8]. Shin and Schweizer [3] used the Kern–Frenkel model [15] and developed a version of self-consistent phonon theory, which predicted the formation of different orientationally ordered hexagonal phases. The structure of these phases was found to be primarily determined by the so-called Janus balance [16], defined by the size of the attractive patch. Experimental study and Monte Carlo simulation of Jiang et al [5] showed the formation of a glass-like phase, instead of the theoretically predicted zigzag phase [3]

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Conclusion