Two-dimensional colloidal fluids exhibiting pattern formation

Chacko, Blesson; Chalmers, Christopher; Archer, Andrew J.

doi:10.1063/1.4937941

Cited by 28 publications

(35 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where for the interaction potential V (r 12 ) depending only on the distance r 12 = |r 1 − r 2 |, V co (r 12 ) = V (r 12 )g(r 12 ).…”

Section: Mesoscopic Volume Fraction Of Particlesmentioning

confidence: 99%

“…where by V we denote the volume of the system, βΩ co [ζ] is given in (1)- (7), and T * , a, A n [ζ] and Z[ζ] are given in (18), (23), (12), and (25)-(26) The expression (30) for the grand potential can be minimized numerically to yield the equilibrium structure in the presence of mesoscopic fluctuations for any value of the chemical potential µ and temperature T .…”

Section: Mesoscopic Volume Fraction Of Particlesmentioning

confidence: 99%

See 1 more Smart Citation

Combined density functional and Brazovskii theories for systems with spontaneous inhomogeneities

Ciach

2018

Soft Matter

View full text Add to dashboard Cite

The low-T part of the phase diagram in self-assembling systems is correctly predicted by known versions of density functional theory (DFT). The high-T part obtained in DFT, however, does not agree with simulations even on the qualitative level. In this work, a new version of DFT for systems with spontaneous inhomogeneities on a mesoscopic length scale is developed. The contribution to the grand thermodynamic potential associated with mesoscopic fluctuations is explicitly taken into account. The expression for this contribution is obtained by methods known from the Brazovskii field theory. Apart from developing the approximate expression for the grand thermodynamic potential that contains the fluctuation contribution and is ready for numerical minimization, we develop a simplified version of the theory valid for weakly ordered phases, i.e. for the high-T part of the phase diagram. The simplified theory is verified by comparison with the results of simulations for a particular version of the short-range attraction long-range repulsion (SALR) interaction potential. Except for the fact that in our theory the ordered phases are stable at lower T than in simulations, a good agreement for the high-T part of the phase diagram is obtained for the range of density that was considered in simulations. In addition, the equation of state and compressibility isotherms are presented. Finally, the physical interpretation of the fluctuation-contribution to the grand potential is discussed in detail.

show abstract

“…where for the interaction potential V (r 12 ) depending only on the distance r 12 = |r 1 − r 2 |, V co (r 12 ) = V (r 12 )g(r 12 ).…”

Section: Mesoscopic Volume Fraction Of Particlesmentioning

confidence: 99%

Section: Mesoscopic Volume Fraction Of Particlesmentioning

confidence: 99%

Combined density functional and Brazovskii theories for systems with spontaneous inhomogeneities

Ciach

2018

Soft Matter

View full text Add to dashboard Cite

show abstract

“…Lamellae and gel-like structures-but no crystal states-arise in another recent simulation study 40 though the relative size of amphiphilic particles and disks is the opposite of ours. A comparison with other works in 2D [28][29][30][31][32][33][34][35][36][37][38] is harder since the models employed are one-component systems and the interest has been almost exclusively in the solid phases rather than in the fluid sector of the phase diagram.…”

Section: The Intermediate σ 3 /σ 2 = 4 Case Shows Intermediate Featurmentioning

confidence: 99%

“…The broad interest in 2D colloidal models is witnessed by a flourishing literature on this topic, aimed at exploring routes to self-assembly into structures of assigned morphology. In most cases, particles have been modeled either through repulsive pair potentials [28][29][30][31][32][33] or as patchy particles, [34][35][36][37][38] both being known for giving stable cluster phases at moderate temperatures. Often, the focus has been on the possibility to create quasicrystalline solids by spontaneous aggregation of the particles; in one instance, 39 the solid phases of a 2D mixture of disks and patchy particles have been analyzed, reporting the existence of many crystalline and quasicrystalline patterns; on the other hand, in a just published paper, 40 a mixture of Janus particles and much smaller disks has been studied for increasing densities, highlighting the existence of an intermediate gel-like regime.…”

Section: Introductionmentioning

confidence: 99%

Two-dimensional mixture of amphiphilic dimers and spheres: Self-assembly behaviour

Prestipino

Munaò

Costa

et al. 2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

The emergence of supramolecular aggregates from simple microscopic interaction rules is a fascinating feature of complex fluids which, besides its fundamental interest, has potential applications in many areas, from biological self-assembly to smart material design. We here investigate by Monte Carlo simulation the equilibrium structure of a two-dimensional mixture of asymmetric dimers and spheres (disks). Dimers and disks are hard particles, with an additional short-range attraction between a disk and the smaller monomer of a dimer. The model parameters and thermodynamic conditions probed are typical of colloidal fluid mixtures. In spite of the minimalistic character of the interaction, we observe-upon varying the relative concentration and size of the two colloidal species-a rich inventory of mesoscale structures at low temperature, such as clusters, lamellæ (i.e., polymer-like chains), and gel-like networks. For colloidal species of similar size and near equimolar concentrations, a dilute fluid of clusters gives way to floating lamellæ upon cooling; at higher densities, the lamellæ percolate through the simulation box, giving rise to an extended network. A crystal-vapour phase-separation may occur for a mixture of dimers and much larger disks. Finally, when the fluid is brought in contact with a planar wall, further structures are obtained at the interface, from layers to branched patterns, depending on the nature of wall-particle interactions.

show abstract

“…2,4 Despite the different origins of the SALR potential in the above examples, the structural and thermodynamic properties of the systems with competing interactions are very similar. 5,[8][9][10][11][12][13][14][15][16][17][18] Moreover, a self-assembly into patterns that are very similar to those observed in amphiphilic systems when the range of attraction is sufficiently large and the repulsion is sufficiently strong takes place. [8][9][10] At sufficiently low temperature the following sequence of ordered phases was predicted for increasing volume fraction of particles by theory and simulation: 10,18-23 spherical clusters, cylindrical clusters, gyroid network of particles, layers of particles, gyroid network of voids, cylindrical voids and finally spherical voids.…”

Section: Introductionmentioning

confidence: 99%

Effects of confinement on pattern formation in two dimensional systems with competing interactions

2016

View full text Add to dashboard Cite

Template-assisted pattern formation in monolayers of particles with competing short-range attraction and long-range repulsion interactions (SALR) is studied by Monte Carlo simulations in a simple generic model [N. G. Almarza et al., J. Chem. Phys., 2014, 140, 164708]. We focus on densities corresponding to formation of parallel stripes of particles and on monolayers laterally confined between straight parallel walls. We analyze both the morphology of the developed structures and the thermodynamic functions for broad ranges of temperature T and the separation L2 between the walls. At low temperature stripes parallel to the boundaries appear, with some corrugation when the distance between the walls does not match the bulk periodicity of the striped structure. The stripes integrity, however, is rarely broken for any L2. This structural order is lost at T = TK(L2) depending on L2 according to a Kelvin-like equation. Above the Kelvin temperature TK(L2) many topological defects such as breaking or branching of the stripes appear, but a certain anisotropy in the orientation of the stripes persists. Finally, at high temperature and away from the walls, the system behaves as an isotropic fluid of elongated clusters of various lengths and with various numbers of branches. For L2 optimal for the stripe pattern the heat capacity as a function of temperature takes the maximum at T = TK(L2).

show abstract

Two-dimensional colloidal fluids exhibiting pattern formation

Cited by 28 publications

References 39 publications

Combined density functional and Brazovskii theories for systems with spontaneous inhomogeneities

Combined density functional and Brazovskii theories for systems with spontaneous inhomogeneities

Two-dimensional mixture of amphiphilic dimers and spheres: Self-assembly behaviour

Effects of confinement on pattern formation in two dimensional systems with competing interactions

Contact Info

Product

Resources

About