How Competitive Interactions Affect the Self-Assembly of Confined Janus Dumbbells

Abstract

We explore the self-assembled morphologies of Janus nanoparticles under cylindrical confinement. Langevin dynamics simulations are employed to study the behavior of two types of dimers inside cylinders with distinct radius. The first type of nanoparticle was modeled using one monomer that interacts by a standard Lennard-Jones potential and another monomer that is modeled using a purely repulsive two length scale shoulder potential. The second type is composed by a Lennard-Jones monomer and a repulsive monomer which interacts by the purely repulsive Weeks-Chandler-Andersen potential, which have only one length scale. The two length scale potential used in the first type of nanoparticle models a monomer with competitive interaction. Our results show that the aggregated structures are completely distinct for each type of nanoparticle. Also, our simulations indicate that the cylinder radius can be used to control the type of self-assembled cluster. Small clusters, tubular and donut-like micelles with central holes, with potential application to molecule encapsulation were observed regarding the nanoparticle specificities and the cylinder radii. Also, bilayer lamellae structures were obtained depending on the type of nanoparticle and the cylinder size.

Waterlike anomalies in a two-dimensional core-softened potential

“…Here, unlike the 3D molecular system, the 2D Brownian system the hierarchy in the anomalies is distinct from the water hierarchy. This change in the hierarchy was already observed in others works, and it is attributed to the changes in the competition between the scales [21,45,54], to the formation of an ordering structure [55] or to the dimensional change from 3D to 2D [56].…”

Molecular Dynamic study of model two-dimensional systems involving Janus dumbbells and spherical particles

“…Finally, we consider systems involving only Janus particles, without the spherical ones. The latter systems resemble those studied by Bordin and Krott [18,19]. The main results are concluded in section 5.…”

“…Among different types of Janus-like particles, the so-called Janus dumbbells that are built of two jointed spheres of different chemical character are one of the simplest "building blocks" and have received much attention recently. In particular, the behavior and self-assembly of Janus dumbbells in bulk two-and three-dimensional phases, as well as at different interfaces have been extensively studied using computer simulations and theoretical approaches, e.g., density functional methods [14][15][16][17][18][19][20][21][22]. Theoretical methods for the description of the systems of anisotropic nanoparticles are similar to the methods used in the studies of systems involving amphiphilic molecules, e.g., surfactants, or even to some extent, of dipolar molecules [23,24].…”

Waterlike anomalies in hard core–soft shell nanoparticles using an effective potential approach: Pinned vs adsorbed polymers

“…The absence of diffusion anomaly when the system exhibits a TMD is not new. It arises in lattice systems in the presence of two length scales interactions depending of the balance between the two length scales [53] and in confinement due the competition between the length scales and the confinement [54]. In this case, it may be related to the fact that here there is no reentrant fluid region -as we saw, this two phenomena were correlated for the U f ixed potential.…”