One-Pot Self-Assembly of Dual-Color Domes Using Mono-Sized Silica Nanoparticles

Spots
with dual structural colors on the skin of some organisms
in nature are of tremendous interest due to the unique function of
their dye-free colors. However, imitation of them requires complicated
manufacturing processes, expensive equipment, and multiple predesigned
building blocks. In this work, a one-pot strategy based on the phase-separation-assisted
nonuniform self-assembly of monosized silica nanoparticles is developed
to construct domes with dual structural colors. In drying poly­(ethylene
glycol)-dextran-based (PEG-DEX) droplets, monosized nanoparticles
distribute nonuniformly in two compartments due to the droplet inner
flow and different nanoparticle compatibility with the two phases.
The dome colors are derived from the self-assembled nanoparticles
and are programmable by regulating the assembly conditions. The one-pot
strategy enables the preparation of multicolor using only one type
of building block. With the dual-color domes, encrypted patterns with
a high volume of contents are designed, showing promising applications
in information delivery.