Modulated phases and structural arrest in colloidal systems with competing interactions

Different types of the lattice spin systems with the competing interactions have rich and interesting phase diagrams. In this study a system with competing nearest-neighbor interaction J1, prolonged next-nearest-neighbor interaction Jp and ternary prolonged interaction Jtp is considered on a Cayley tree of arbitrary order k. To perform this study, an iterative scheme is developed for the corresponding Hamiltonian model. At finite temperatures several interesting properties are presented for typical values of α = T/J1, β = −Jp/J1 and γ = -Jtp/J1. This study recovers as particular cases, previous work by Vannimenus1 with γ = 0 for k = 2 and Ganikhodjaev et al.2 in the presence J1, Jp, Jtp with k = 2. The variation of the wavevector q with temperature in the modulated phase and the Lyapunov exponent associated with the trajectory of our iterative system are studied in detail.

Download Full-text

Structural and Dynamical Behaviour of Colloids with Competing Interactions Confined in Slit Pores

International Journal of Molecular Sciences ◽

10.3390/ijms222011050 ◽

2021 ◽

Vol 22 (20) ◽

pp. 11050

Author(s):

Horacio Serna ◽

Wojciech T. Góźdź ◽

Eva G. Noya

Keyword(s):

Hexagonal Phase ◽

Dynamical Behaviour ◽

Narrow Slit ◽

Colloidal Systems ◽

Pore Width ◽

Competing Interactions ◽

Lamellar Phases ◽

Bulk System ◽

The One ◽

Slit Pores

Systems with short-range attractive and long-range repulsive interactions can form periodic modulated phases at low temperatures, such as cluster-crystal, hexagonal, lamellar and bicontinuous gyroid phases. These periodic microphases should be stable regardless of the physical origin of the interactions. However, they have not yet been experimentally observed in colloidal systems, where, in principle, the interactions can be tuned by modifying the colloidal solution. Our goal is to investigate whether the formation of some of these periodic microphases can be promoted by confinement in narrow slit pores. By performing simulations of a simple model with competing interactions, we find that both the cluster-crystal and lamellar phases can be stable up to higher temperatures than in the bulk system, whereas the hexagonal phase is destabilised at temperatures somewhat lower than in bulk. Besides, we observed that the internal ordering of the lamellar phase can be modified by changing the pore width. Interestingly, for sufficiently wide pores to host three lamellae, there is a range of temperatures for which the two lamellae close to the walls are internally ordered, whereas the one at the centre of the pore remains internally disordered. We also find that particle diffusion under confinement exhibits a complex dependence with the pore width and with the density, obtaining larger and smaller values of the diffusion coefficient than in the corresponding bulk system.

Download Full-text

Modulated Phases Observed in Reacting Polymer Mixtures with Competing Interactions

Macromolecules ◽

10.1021/ma961542x ◽

1997 ◽

Vol 30 (6) ◽

pp. 1643-1650 ◽

Cited By ~ 38

Author(s):

Asuka Harada ◽

Qui Tran-Cong

Keyword(s):

Polymer Mixtures ◽

Competing Interactions ◽

Modulated Phases

Download Full-text

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

Soft Matter ◽

10.1039/c9sm02002k ◽

2020 ◽

Vol 16 (3) ◽

pp. 718-727 ◽

Cited By ~ 3

Author(s):

Horacio Serna ◽

Eva G. Noya ◽

Wojciech T. Góźdź

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

Cross Section ◽

Grand Canonical Monte Carlo ◽

Colloidal Systems ◽

Competing Interactions ◽

Grand Canonical

Using grand canonical Monte Carlo simulations, we investigate how the structure of a colloidal fluid with competing interactions can be modified by confinement in channels with different cross-section geometries and sizes.

Download Full-text

On the Role of Competing Interactions in Charged Colloids with Short-Range Attraction

Annual Review of Condensed Matter Physics ◽

10.1146/annurev-conmatphys-061020-053046 ◽

2020 ◽

Vol 12 (1) ◽

Author(s):

José Ruiz-Franco ◽

Emanuela Zaccarelli

Keyword(s):

Short Range ◽

Condensed Matter ◽

Annual Review ◽

Publication Date ◽

Colloidal Systems ◽

Competing Interactions ◽

Charged Colloids ◽

Open Questions ◽

Cluster Phase

In this review, we discuss recent advances in the investigation of colloidal systems interacting via a combination of short-range attraction and long-range repulsion. The prototypical examples of this phenomenology are charged colloids with depletion interactions, but the results apply, to a large extent, also to suspensions of globular proteins, clays, and, in general, to systems with competing attractive (hydrophobic) and repulsive (polar) contributions. After a brief introduction to the problem, we focus on the three disordered states that characterize these systems: equilibrium cluster phase, equilibrium gel, and Wigner glass of clusters. We provide a comparison of their static and dynamic observables, mainly by means of numerical simulations. Next, we discuss the few available studies on their viscoelastic properties and on their response to an external shear. Finally, we provide a summary of the current findings and also raise the main open questions and challenges for the future in this topic. Expected final online publication date for the Annual Review of Condensed Matter Physics, Volume 12 is March 10, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Download Full-text