Complex structures generated by competing interactions in harmonically confined colloidal suspensions

Abstract

We investigate the structural properties of colloidal particle systems interacting via an isotropic pair potential and confined by a three-dimensional harmonic potential. The interaction potential has a repulsive-attractive-repulsive profile that varies with the interparticle distance (also known as a 'mermaid' potential). We performed Langevin dynamics simulations to find the equilibrium configurations of the system. We show that particles can self-assemble in complex structural patterns, such as compact disks, fringed disks, rods, spherical clusters with superficial entrances among others. Also, for particular values of the parameters of the interaction potential, we could identify that some configurations were formed by quasi two-dimensional (2D) structures which are stable for 2D systems.

The influence of confinement on the structure of colloidal systems with competing interactions

“…Different types of confinement may be used to promote the formation of structures beyond the well-known ordered phases in bulk. 10,11 The process of selfassembling may be highly useful for development of new technologies with applications in different fields like drug delivery, bioelectronics and catalysis. 12,13 In particular, colloidal particles confined in channels of different geometries are used to build wave-guide devices with applications in sensing 14,15 In this article we investigate, by means of Monte Carlo simulations in the grand canonical ensemble, how the structures stable in bulk can be altered by confinement.…”

Soft core fluid with competing interactions at a hard wall

“…In [38], the structure and adsorption of a system with competing interactions confined by an attractive wall was investigated by means of computer simulations. Phase behavior of a harmonically confined colloidal suspension has been considered as well [39]. In [40] the authors developed a mesoscopic theory for self-assembling systems near a planar confining surface.…”

Ordering and Dynamics of Interacting Colloidal Particles under Soft Confinement

“…However, recent works have highlighted the importance of the role played by the softness of the confining mechanism [6][7][8][9][10]16,17]. For example, a colloidal system whose particles interact with a potential that has a short-ranged attraction and a long-ranged repulsion and confined by a harmonic-potential experiences a self-assembly process that leads to exciting and complex structural patterns [18,19].…”