Clusters formed by dumbbell-like one-patch particles confined in thin systems

Abstract

Performing isothermal-isochoric Monte Carlo simulations, I examine the types of clusters that dumbbell-like one–patch particles form in thin space between two parallel walls, assuming that each particle is synthesized through the merging of two particles, one non-attracting and the other attracting for which, for example, the inter-particle interaction is approximated by the DLVO model . The shape of these dumbbell-like particles is controlled by the ratio of the diameters q of the two spherical particles and by the dimensionless distance l between these centers. Using a modified Kern–Frenkel potential, I examine the dependence of the cluster shape on l and q. Large island-like clusters are created when $$q<1$$ q < 1 . With increasing q, the clusters become chain-like . When q increases further, elongated clusters and regular polygonal clusters are created. In the simulations, the cluster shape becomes three-dimensional with increasing l because the thickness of the thin system increases proportionally to l.

Amphiphilic Janus Particles Confined in Symmetrical and Janus-Like Slits

“…The wall separation is assumed to be L z . The model of amphiphilic Janus particle used here is essentially the same as described in earlier works. ,,, The Janus particles consist of two hemispheres; the parts named A are attractive while the parts R are repulsive. The interaction potential between two Janus particles is expressed as a sum of the hard-sphere potential, v JJ hs , and the anisotropic contribution v J J = v J J h s − v J J s w ( r 12 ) ( û 1 − û 2 ) · boldr̂ 21 where the vectors r 1 and r 2 characterize the positions of the interacting particles, r 12 = | r 12 | = | r 1 – r 2 |, boldr̂ 21 = boldr 21 / | r 21 | , and boldû 1 , boldû 2 are the unit patch orientation vectors; the vector boldû i points toward the repulsive ( R ) part of the particle i ( i = 1, 2), and the v J J s w ( r 12...…”

“…The model of amphiphilic Janus particle used here is essentially the same as described in earlier works. 25,35,36,39 The Janus particles consist of two hemispheres; the parts named A are attractive while the parts R are repulsive. The interaction potential between two Janus particles is expressed as a sum of the hardsphere potential, v JJ hs , and the anisotropic contribution…”

“…From a cognitive point of view, it is very interesting to discuss the self-assembly of JPs in different pores. − , Several theoretical works dealt with the behavior of JPs in two-dimensional channels. − Molecular dynamic simulations were carried out for Janus disks in a two-dimensional plane, which were trapped in a one-dimensional harmonic potential, and for Janus spheres in a circular symmetric harmonic trap . In these systems, various membrane-like morphologies were found.…”

“…The behavior of JPs in three-dimensional channels has been studied using density functional theory , and molecular simulations. − , Rosenthal and Klapp have investigated amphiphilic JPs in slits and discussed the competition between planar structures preferred by the surfaces and nonplanar (micellar) structures induced by particle–particle interactions. They proved that the surfaces can stabilize bilayer structures characterized by a high degree of ordering relative to the walls.…”

“…Several interesting phenomena were observed in such systems, namely, two-dimensional “crystallization of clusters”, surface-induced formation of “levitating” slabs, and “inverted” adsorption in Janus-like pores . Clusters formed by dumbbell-like JPs confined in thin space between two parallel walls have been also discussed …”