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

Abstract

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.

Heterogeneous Self-Assembly of a Single Type of Nanoparticle Modulated by Skin Formation

“…(100) planes of the FCC lattice are formed in the region adjacent to the skin layer near the TCL of the droplet. The two orientation planes generate binary photonic bandgaps and binary structural colors due to the different lattice constants ( D ), following Bragg’s law (Figure f,g): λ = 2 × italicD × normalΣ ( n i × V i ) 2 − sin 2 nobreak0em.25em⁡ θ where λ is the diffraction wavelength, θ is the incident angle of light, n i and V i are the refractive indexes and the volume fractions of each component of the ordered structure, respectively. In this work, both the incident angle of light and the viewing angle are 0° (Figure S6).…”

“…One typical example that needs a heterogeneous structure is the PC heterojunction consisting of two types of photonic crystals . The heterogeneous structure enables a PC heterojunction to show binary bandgaps and can thus be used in multicolor palettes, optical diodes, optical splitters, and lasers . Generally, to obtain such heterogeneous structures, human interventions, including applying a tunable external electric or magnetic field, , or photolithography methods, , are indispensable during the preparation process, which poses additional steps and difficulties for the fabrication path.…”

Three-Dimensionally Printed, Vertical Full-Color Display Pixels for Multiplexed Anticounterfeiting

“…Since counterfeiting has emerged as a global issue, novel and advanced strategies are in great demand for data storage and encryption to prevent information leakage. − To this end, various materials, − structuring strategies, ,− and data processing algorithms ,,, have been devised. Creating high-resolution, sophisticated anticounterfeiting patterns has mostly relied on photolithography, ,,, nanoimprinting, ,, and laser engraving, − which are energy-intensive and/or chemically deleterious and difficult to perform on valuable products.…”