Two-dimensional binary mixtures of patchy particles and spherical colloids

Abstract

Using Monte Carlo simulation we study two dimensional mixtures of patchy and spherically symmetric particles. Such mixtures can be synthesized experimentally by covering colloids with appropriate types of DNA strands [L. Feng, et al., Adv. Mater., 2013, 25, 2779]. We focus on finding out the ordered structures that can be formed in such systems. The type of ordered phase strongly depends on the valency, size and binding energy of the patchy particles. If the patch size is small enough, i.e. it allows only one spherically symmetric particle to be bound, the ordered structure follows either a hexagonal or a tetragonal pattern depending on the valency of the patchy particles. Moreover, we find stable quasicrystals of dodecagonal symmetry. Additional structures can be obtained if the patches are larger and the binding energy is higher. Depending on the valency of the patchy particles we find either lanes or branched structures forming polygons of the spherically symmetric particles with few patchy particles inside. For pentavalent patchy particles we find stable quasicrystals of decagonal symmetry.

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

“…The present results can be compared with those in Ref. 39, where a mixture of disks and patchy particles with two to five patches is studied. At relatively high packing fractions, various types of solid-vapour separations have been reported at low temperature, similarly as found in our 20% mixture.…”

“…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. We argue that each of these studies deserves its own interest since it provides suggestions that can be helpful for a better understanding of the three-dimensional case.…”

Patchy Nanoparticle Synthesis and Self-Assembly

“…The same group also suggests through rational design of patch shape and symmetry that triblock patchy particles can selectively crystallize into tetrastack lattice with unique photonic properties, and even a colloidal clathrate-like structure [149]. Other structures including icosahedra, tetrahedra, square pyramids [8], helical structures [150], quasicrystals of dodecagonal symmetry [35,151], and open lattices [152,143] (Figure 9a and b) with high structural selectivity over other polymorphs are studied (Figure 9c) [153]. Together with recent studies in mechanical and functional properties of the exotic structures formed as bottom-up [154,155], these theoretical studies have been paving ways to experimentally achieve novel functional nanostructures.…”

“…In recent years, both in experiment and theory, researchers have been trying to identify the design parameters for the patches to direct assembly behaviors of patchy nanoparticles. Some of those parameters are size [28], composition [29], surface chemistry [30,31], symmetry [32], number of patches per particle [33,34], as well as the binding energy between the patches [35]. While understanding the key design parameters is complicated because the impact of each is often hard to decouple from one another, some well-established design rules for patchy particles are listed herein.…”

Percolation of functionalized colloids on patterned substrates

“…Patchy colloids are ideal building blocks to obtain e.g. empty liquids [23][24][25][26], colloidal micelles [27], quasicrystals [28], and complex lattices [29,30].…”