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.

Seeded-Growth of Silica Rods from Silica-Coated Particles

“…Particularly interesting colloidal building blocks are colloidal silica rod-like structures. Silica rods with high uniformity can be made via a one-pot wet-chemical synthesis method, are low-cost, inert, biocompatible, and highly tunable and already show great potential for many novel materials such as advanced coatings (superhydrophobic and nonfouling), thin films for solar cells, porous composites, , and advanced optical materials because of their ability to form liquid crystal − and plastic crystal phases. − In addition, they find applications as interesting model systems to study the influence of anisotropy on phase behavior on the single particle level in 3D. ,− …”

Block Copolymer as a Surface Modifier to Monodisperse Patchy Silica Nanoparticles for Superhydrophobic Surfaces

“…One is to construct surface roughness on initially hydrophobic materials by various methods including wax solidification, vapor deposition, plasma etching, photolithography, and so on. The other one is to modify a rough hydrophilic surface with low-surface-energy chemicals or deposit superhydrophobic colloids onto many types of surfaces of substrates such as paper, glass, wood, fiber, metals, and so on. − Inspired by rose petals, lotus leaves, and other organisms in nature, raspberry-like patchy nanoparticles (NPs) are promising candidates for the fabrication of superhydrophobic surfaces because of their hierarchical structure. − Small silica (SS) NPs (70 nm) were covalently grafted onto the big ones (700 nm) to form raspberry-like silica NPs, which were further covered by poly­(dimethyl-siloxane) layer to obtain superhydrophobic surfaces . Similarly, raspberry-like polymer particles were produced via grafting small glycidyl-bearing particles (212 nm) onto the big ones (332 nm), leading to the formation of superamphiphobic coatings after further fluorination .…”

A Partially Graphitic Mesoporous Carbon Membrane with Three-Dimensionally Networked Nanotunnels for Ultrasensitive Electrochemical Detection

“…Herein, we report a facile strategy for preparing a hierarchically porous partially graphitic carbon (HPGC) membrane (Figure ) and applying the HPGC membrane as a monolithic electrode matrix for constructing highly sensitive electrochemical (bio)­sensors (Figure ). A three-dimensionally assembled silica nanowire (NW) membrane, as we recently reported, is applied as a hard template to tune the macroscopic dimensions (size and thickness) of the HPGC membrane and generate three-dimensionally networked nanotunnels (∼40–80 nm in diameter) inside the membrane. Non-ionic surfactant Pluronic F127 is used as a porogen, which is added to the carbon precursor solution, to produce ordered mesopores (∼6.5 nm in diameter) in the carbon walls of the nanotunnels.…”