Elaborately Aligning Bead‐Shaped Nanowire Arrays Generated by a Superhydrophobic Micropillar Guiding Strategy

Abstract

Bead‐shaped 1D structures are of great interest due to their unique applications in mesoscopic optics/electronics and their specific ability to collect tiny droplets. Here, a novel method to fabricate aligning bead‐shaped nanowire arrays assisted by highly adhesive superhydrophobic surfaces based on a micropillar guiding strategy is presented. Different from previous fabrication techniques, bead‐shaped nanowires generated in this method are strictly oriented in a large scale. Rayleigh instability, which occurs at ultralow polymer concentration, can introduce bead‐shaped nanowires at the cost of structural strength. Thus, PS spheres are more suitable to serve as bead building blocks to generate firm bead‐shaped nanowire arrays. The bead number is tunable by tailoring the polystyrene‐sphere/polyvinyl‐formal ratio. Furthermore, as‐prepared bead‐shaped nanowires have the unique ability to directionally drive tiny drops and collect coalesced microdroplets when placed in mist. With an increase in humidity, the nanowires show a segmented swelling behavior in the “bead” parts whereas the “joint nanowire” parts remain the same. Because such bead‐shaped nanowires are formed regularly, collected microdroplets upon the beads would not interact with each other. The findings offer new insight into the alignment of bead‐shaped nanostructures and might provide promising opportunities in fundamental research and for industrial applications.

Printable Functional Chips Based on Nanoparticle Assembly

“…[111] www.small-journal.com oriented bead-shaped nanowire arrays. [ 124 ] The bead number on the nanowire arrays can be tailored by diverse ratios of PS-sphere/polymer, as shown in Figure 9 b and c. When a polymer in organic solution was dropped on an oleophilic surface with micropillar structure, a thin layer of liquid fi lm formed. Due to organic solvent evaporation, the liquid fi lm breaks around the micropillar and forms continuous liquid bridges in gaps of the pillars.…”

“…On superhydrophobic pillar-structure substrates with high adhesion, nanowire can be successfully guided into various positions through the design of micropillar arrangements, TCL shrinkage directions, and liquid bridges rupture models. [122][123][124] In detail, when a droplet of polymer solution was controlled to slip on this surface, due to the TCL rapidly inward shrink process, liquid films with "U" shape were elongate vertically, and yielded a liquid bridge between each pair of adjacent micropillars, as shown in Figure 9a. The method to fabricate bead-shaped NP-assembled nanowire arrays with the ability of directional driving and collecting tiny droplets in mist was developed recently.…”

“…Reproduced with permission. [124] www.small-journal.com polymer solutions, Sirbuly's group developed this piezoelectric ink to generate 3D microsturctures under UV light. [ 135 ] With UV irradiation, the polymer crosslinks and introduces the NPs into the polymer backbones through the chemical groups on its surface.…”

Generating Aligned Micellar Nanowire Arrays by Dewetting of Micropatterned Surfaces

“…In contrast with this, a ‘bottom‐up’ approach based on spontaneous self‐assembly of organic material, which is the main organizational mechanism found in nature, provides a simpler route to form desired nanostructures. Moreover, these organic nanowires are also highly deformable since they are assembled from molecular units with weak intermolecular interactions, such as hydrogen bonds, π–π stacking and van der Waals forces . Although these organic nanowires can be prepared easily, most of them end up in a disordered orientation after the fabrication process.…”

Precisely Patterning Graphene Sheets through a Liquid‐Bridge Induced Strategy

“…Therefore, on‐demand positioning of graphene onto desired substrates remains a relatively unexplored subject and a significant scientific challenge. Recently, a “liquid bridge induced assembly” strategy has been reported to successfully assemble small molecules, polymers, biomarcromolecules, nanoparticles and microspheres . Diverse building blocks insides liquid bridges can be guided to assemble into one dimensional architectures with precisely positioning, allowing a promising avenue for precise graphene patterning.…”