Self-assembly of chromatic patchy particles with tetrahedrally arranged patches

TL;DR

This paper investigates the self-assembly of patchy particles with tetrahedral patches, revealing challenges in selectively forming cubic diamond structures due to competing phases and frustration effects, with implications for photonic applications.

Contribution

It demonstrates that 1:1 mixtures of identical patchy particles cannot selectively form cubic diamond due to frustration, and explains the limitations in binary systems under confinement.

Findings

Mixtures always form both hexagonal and cubic diamond phases.

Stacking hybrids are more common in binary systems across various patch sizes.

Selective formation of cubic diamond is hindered by frustration and competing phases.

Abstract

The achievement of selectivity in the formation of cubic diamond is challenging due to the emergence of competing phases such as its hexagonal polymorph or clathrates possessing similar free energy. Although both polymorphs exhibit a complete photonic bandgap, the cubic diamond exhibits it at lower frequencies than the hexagonal counterpart, positioning him as a promising candidate for photonic applications.Herein, we demonstrate that the 1:1 mixture of identical patchy particles cannot selectively form the cubic diamond polymorph due to the frustrations present in the system that are manifested in the primary adsorption layer and propagate as the film grows. We provide a plausible} explanation why the binary system under confinement, resembling interactions between the complementary DNA bases cannot yield the selectivity in the formation of cubic diamond crystals which is based on the similarities to the antiferromagnetic systems. We always observe the mixture of both hexagonal and cubic diamonds, however, the formation of such stacking hybrids is observed for a wider range of patch sizes compared to the one-component system.