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

Abstract

Self-assembly of colloidal nanoparticles has generated tremendous interest due to its widespread applications in structural colorations, sensors, and optoelectronics. Despite numerous strategies being developed to fabricate sophisticated structures, the heterogeneous self-assembly of a single type of nanoparticle in one step remains challenging. Here, facilitated by spatial confinement induced by a skin layer in a drying droplet, we achieve the heterogeneous self-assembly of a single type of nanoparticle by quickly evaporating a colloid-poly (ethylene glycol) (PEG) droplet. During the drying process, a skin layer forms at the droplet surface. The resultant spatial confinement assembles nanoparticles into face-centered-cubic (FCC) lattices with (111) and (100) plane orientations, generating binary bandgaps and two structural colors. The self-assembly of nanoparticles can be regulated by varying the PEG concentration so that FCC lattices with homo- or heterogeneous orientation planes can be prepared on demand. Besides, the approach is applicable for diverse droplet shapes, various substrates, and different nanoparticles. The one-pot general strategy breaks the requirements for multiple types of building blocks and predesigned substrates, extending the fundamental understanding underlying colloidal self-assembly.

Colloidal Photonic Composites with a Long-Range Order by Hot-Pressing Polymer Brush-Grafted Silica Colloids

“…The structural colors and mechanical properties of CPCs mainly depend on the arrangement of the colloidal particles within the polymeric matrix, which are primarily determined by their preparation process. , Generally, a self-assembly strategy is usually adopted for preparing CPCs via capillary forces generated by solvent volatilization to drive the colloidal particles into an orderly arrangement. − After infusing polymers into colloidal arrays, highly ordered CPCs can be obtained. , Niu et al fabricated self-healable CPCs with high toughness by integrating a preassembled PS@SiO 2 colloidal array with a polyurethane elastomer. Specifically, the PS@SiO 2 colloidal array with long-range order obtained by the direct template method under heat-assisted solvent evaporation was infiltrated with a PU precursor, followed by curing for 2 h at 100 °C.…”

Biomimetic Anticoagulated Porous Particles with Self‐Reporting Structural Colors

“…As a representative photonic crystal (PhC) material, the inverse opal is featured with highly ordered hexagonal close packing and interconnected cavity structures. [ 26 , 27 , 28 , 29 , 30 , 31 ] The sufficient specific surface area of the inverse opal hydrogel skeleton provided abundant binding sites between functional groups (sulfonic and carboxyl) and multiple coagulation factors. Such chemical anchoring of the anticoagulation reagents will not only achieve extracorporeal anticoagulation of blood but also avoid the risk of residuals in the blood and improve the biosafety.…”