Synthesis of Discrete Alkyl‐Silica Hybrid Nanowires and Their Assembly into Nanostructured Superhydrophobic Membranes

Abstract

We report the synthesis of highly flexible and mechanically robust hybrid silica nanowires (NWs) which can be used as novel building blocks to construct superhydrophobic functional materials with three-dimensional macroporous networks. The hybrid silica NWs, with an average diameter of 80 nm and tunable length of up to 12 μm, are prepared by anisotropic deposition of the hydrolyzed tetraethylorthosilicate in water/n-pentanol emulsions. A mechanistic investigation reveals that the trimethoxy(octadecyl)silane introduced to the water-oil interface in the synthesis plays key roles in stabilizing the water droplets to sub-100 nm and also growing a layer of octadecyl groups on the NW surface. This work opens a solution-based route for the one-pot preparation of monodisperse, hydrophobic silica NWs and represents an important step toward the bottom-up construction of 3D superhydrophobic materials and macroporous membranes.

Highly Stable Luminous “Snakes” from CsPbX3 Perovskite Nanocrystals Anchored on Amine-Coated Silica Nanowires

“…PXRD patterns demonstrate that all the composites of CsPbX3@CA-SiO2 crystalize in the orthorhombic perovskite structure (Figure 4c The composite can be readily assembled into a compact hierarchically structured porous membrane by vacuum filtration. 47 Membranes were prepared by dropping the CsPbBr3@CA-SiO2 solution onto a piece of filter paper under continuous vacuum and results in a self-woven membrane tightly attached to the substrate (Figure 5a and S10a). SEM images reveal the formation of a porous membrane made of entangled CsPbBr3@CA-SiO2 NWs, similar to the ubiquitous ramen noodle (Figure 5b and c), and free of stray perovskite particles.…”

“…This work presents an effective strategy for growing perovskite NCs onto functional matrices to form perovskite-based composites, paving the way for future optoelectronic applications.Experimental SectionsMaterials and Chemicals: PbBr2 (99.90%), Cs2CO3 (99.99%), octadecene (ODE, 90%), oleic acid (OA, 90%, AR), oleylamine (OLA, 90%, AR), 3-aminopropyl-triethoxysilane (APTES, 99%), )silane (TMODS, 90%) were purchased from Aladdin and used as received without purification. All the other solvents were used as received without any purification.Preparation of octadecyl/propylamine capped silica (CA-SiO2) NWs:The octadecyl/propylamine capped silica (CA-SiO2) NWs were synthesized following a modified procedure 47. In a typical synthesis, polyvinylpyrrolidone (1.0 g, Mw=24 kDa) was dissolved in n-pentanol (8.0 ml) in a 50 mL centrifugation tube.…”

A Library of Multipurpose Supramolecular Supergelators: Fabrication of Structured Silica, Porous Plastics, and Fluorescent Gels

“…As the thickness of the gel fibers can be tuned by changingt he concentration of the gelator,t his methodology may be useful to make porousp olystyrenes with tunable pore diameters. Silica microstructures are of great interestf or variousa pplications, such as hydrophobic coating, [20] composite materials, [21] light scatterers in solar cells, [22] biomedical fields, [23] separation, [24] and so on. [25] Shinkai et al used organogels derived from cholesterol as templates for the polymerization of TEOS to produce variousn anostructured silica architectures, including ribbons, helices, rods, and tubes.…”

Synthesis of Chemically Asymmetric Silica Nanobottles and Their Application for Cargo Loading and as Nanoreactors and Nanomotors

“…The synthesis of the chemically asymmetric silica NBs is inspired by our recent work on synthesizing hydrophobic silica nanowires, which were anisotropically grown in a water/oil emulsion system . Our current work uses (3‐chloropropyl)trimethoxysilane (CPTMS) with a mildly hydrophobic 3‐chloropropyl group instead of the highly hydrophobic trimethoxy(octadecyl)silane (OTMS) previously used to prepare the high aspect ratio nanowires.…”