Monte-Carlo simulation of string-like colloidal assembly

TL;DR

This paper uses Monte Carlo simulations to explore how polymer-grafted colloidal particles self-assemble into string-like structures at low temperatures and high densities, revealing a phase diagram linked to percolation phenomena.

Contribution

It introduces a simulation study of string-like colloidal assembly with a validated interaction potential, connecting phase transitions to percolation and critical phenomena.

Findings

String-like assemblies form at low temperature and high density.

The average string length diverges at the intersection of melting and percolation lines.

The phase diagram shows a critical point similar to Ising spin systems.

Abstract

We study structural phase transition of polymer-grafted colloidal particles by Monte Carlo simulations on hard spherical particles. The interaction potential, which has a weak repulsive step outside the hard core, was validated with use of the self-consistent field calculations. With this potential, canonical Monte Carlo simulations have been carried out in two and three dimensions using the Metropolis algorithm. At low temperature and high density, we find that the particles start to self-assemble and finally align in strings. By analyzing the cluster size distribution and string length distribution, we construct a phase diagram and find that this string-like assembly is related to the percolation phenomena. The average string length diverges in the region where the melting transition line and the percolation transition line cross, which is similar to Ising spin systems where the percolation transition line and the order-disorder line meet on the critical point.