Self-assembly of anisotropic red blood cell (RBC)-like colloidal particles

Abstract

Non-spherical colloidal particles, as basic building blocks, exhibit special capability in constructing novel materials. In this work, red blood cell (RBC)-like, anisotropic particles were synthesized and the self-assembly of the RBC-like particles was then carried out at the air-water interface. Subsequently, multilayer 3D structured colloidal crystals were also fabricated. The as-prepared colloidal crystal film displays beautiful Bragg diffraction, which can be used to construct a photonic crystal. After that, the self-assembly of binary colloidal particles was explored to design well-patterned binary colloidal crystals. This facile self-assembly approach to prepare colloidal crystals may extend to other anisotropic building blocks, providing guidance for the fabrication of more complex and flexible materials.

Anisotropic Hexagonal Particles Induced by the Double-Solvent Swelling Method

“…The RBC-like particles were designed and fabricated by one-pot dispersion polymerization. , Then the RBC-like particles were self-assembled into monolayer crystal arrays via the interface self-assembly method. , As shown in Figure a, the particles were arranged in a monolayer hexagonal close-packed arrangement, forming high-quality crystal arrays and possessing consistent orientations. Figure b is the AFM image of the crystal arrays where the different hues represent different heights ranging from the highest part (represented by the letter “A”) to the lowest part of the dimple (represented by the letter “B”).…”

“…The large-area self-assembly particle arrays were prepared by convective self-assembly at the air–water interface. , In brief, the 2 wt % suspension of RBC-like Janus particles was prepared (the solvent contains 60 wt % of ethanol and 40 wt % of deionized water) and sonicated for 10 min. A 100 μL amount of the above suspension was added to the surface of a Petri dish (diameter is 6 cm) filled with water.…”

“…Therefore, in this work, we designed and fabricated the regular hexagonal particles which were inspired by the natural compound eye anisotropic structure. The process is illustrated in Scheme ; the anisotropic red blood cell (RBC)-like particles were fabricated and self-assembled into large-scale monolayer colloidal crystal arrays according to our previous work. − After that, the close-packed particle arrays were used for the post-treatment strategy to prepare hexagonal particles. First, the crystal arrays were immersed in the double-solvent system ( N , N -dimethylformamide (DMF) and tetraethyl orthosilicate (TEOS)) at 60 °C.…”

Synthetic Strategies for Polymer Particles with Surface Concavities

“…Dimpled polymer particles have been conveniently prepared via various polymerization techniques, either seeded polymerization [ 53–93 ] or one‐step polymerization. [ 94–108 ] In most cases, the polymerization recipe involves the use of a cross‐linker (e.g., divinylbenzene (DVB)) or a comonomer that can form rigid shell during polymerization (e.g., 3‐(trimethoxysilyl)propyl methacrylate (TPM)). And there are two typical dimple formation mechanisms: one is based on phase separation between cross‐linked domains and unreacted monomers caused by the uneven distribution of cross‐linkers; and another is based on buckling of the outer elastic shell, as discussed below.…”

“…In this strategy, dimpled particles are usually prepared by one-step copolymerization of the monomers. Various polymerization techniques including emulsion polymerization, [84][85][86][87] surfactant-free emulsion polymerization, [88][89][90][91][92][93] miniemulsion polymerization, [94,95] dispersion polymerization [96][97][98][99][100][101][102][103][104][105][106][107] have been employed. We are also aware that there is a special example on synthesis of bowl-shaped polydopamine nanocapsules by solution polymerization.…”