Spray-Coating of Superhydrophobic Coatings for Advanced Applications

Superhydrophobic coatings are widely applicable, e.g., as self-cleaning surfaces or water–oil separation membranes, yet their wider usage is impeded due to costs of fabrication, size, or substrate limitation. Spray-coating is a versatile coating procedures and might offer a good solution for the fabrication of these superhydrophobic coatings, due to the fact that coatings can be fabricated on various materials in a simple, fast, and inexpensive manner. Most procedures rely on hybrid coatings of hydrophobized nanoparticles and a polymeric matrix, which have several drawbacks including the easy loss of nanoparticles and difficult waste handling. Here, the fabrication of the superhydrophobic material, called Fluoropor, for the first time, by spray-coating on various substrates including metals, tissues, concrete, and glass is presented. It is fabricated by spray-coating a mixture of a highly fluorinated monomer blended with porogens followed by photopolymerization. The superhydrophobicity of the material relies on the porous structure on the micro-/nanoscale across the bulk material and does not require any nanoparticles. Excellent self-cleaning ability of these coatings, resistance against thermal and abrasive impact, and their application as oil–water separation membranes are shown. This versatile applicability is highly promising for real-world application as self-cleaning coatings or oil–water separating membranes.     

Construction of mechanically robust superamphiphobic surfaces on fiber using large particles

Superamphiphobic surfaces have attracted the attention of researchers because of their broad application prospects. Currently, superamphiphobicity is primarily achieved by minimizing the solid–liquid contact area. Over the past few decades, researchers have primarily focused on using physical deposition methods to construct superamphiphobic surfaces using fine-sized nanoparticles (< 100 nm). However, porous hollow SiO₂ particles (PH-SiO₂), which are typically large spheres, have a highly hierarchical structure and can provide lower solid–liquid contact fractions than those provided by fine-sized particles. In this study, we used PH-SiO₂ as building blocks and combined them with poly (dimethylsiloxane) to construct a mechanically robust coating on fiber by spray-coating. After chemical vapor deposition treatment, the coating exhibited excellent superamphiphobicity and could repel various liquids, covering a wide range of surface tensions (27.4–72.0 mN·m⁻¹).     

Uniform graphene oxide films fabrication via spray-coating for sensing application

Abstract

A spray-coating technique for deposition of thin uniform graphene oxide films with a thickness of several tens of nanometers was developed. Among distinctive features of the technique is the low substrate heating temperature, which allows preserving most oxygen-containing functional groups and coat a wide range of substrates. The morphology of the spray-coated graphene oxide films with flakes of different lateral sizes was investigated. The local laser-induced photo-thermal reduction of thin graphene oxide thin films was demonstrated. The sensitivity of reduced graphene oxide to water vapor was also measured. Spray-coating and laser reduction techniques can be further applied for humidity sensor fabrication.     

超音速活性电弧喷涂技术在电力行业中的应用

本文重点介绍超音速活性电弧喷涂技术的原理、特点，并列举其在电力行业关键设备修复与预保护中的应用实例。     

Spraying Perovskite Intermediate Enabling Inch-Scale Microwire Film Fabrication for Integration Compatible Efficient-Photodetectors Array

Metal halide perovskite microwires (MWs) have emerged as promising photoactive materials for highly efficient photodetectors (PDs). However, large-scale MWs film fabrication is still a formidable challenge for achieving integration compatible perovskite PDs arrays, owing to precipitation and structure crushing of MWs during deposition and annealing. Herein, a strategy of fabrication of inch-scale perovskite MWs films is presented by depositing perovskite intermediate suspension through spray-coating, which addresses the trade-off present between the high flatness of MWs film and its large-scale fabrication. The single crystalline perovskite MWs weave a film with high enough flatness rendering narrow performance distribution of high efficiency on the 7 × 7 PDs arrays. The formamidinium lead iodide (FAPbI₃) PDs arrays show average responsivity and detectivity of (1.60 ± 0.46) A W⁻¹ and (1.49 ± 0.50) × 10¹² Jones. The methanaminium lead iodide (MAPbI₃) PDs arrays show average responsivity and detectivity of (0.065 ± 0.046) A W⁻¹ and (2.54 ± 0.77) × 10¹¹ Jones. The champion PDs based on FAPbI₃ MWs film and MAPbI₃ MWs film show detectivity of 1.26 × 10¹³ and 9.67 × 10¹¹ Jones, which are much higher than that of corresponding polycrystalline films and located on the top ranking of similar devices.     

二氧化硅纳米颗粒/硅树脂复合超疏水功能涂层的制备和性能研究

将二氧化硅纳米颗粒和硅树脂制成混合液,采用喷涂法(spray-coating)制备出了具备超疏水性的复合涂层.研究了二氧化硅、硅树脂不同含量配比对涂层疏水性能的影响,结果表明复合涂层的接触角随二氧化硅含量的增加而增加.在二氧化硅含量大于3%(质量分数)时,涂层显现超疏水性;当二氧化硅含量为3%(质量分数)、硅树脂含量为7%(质量分数)时,涂层与水的接触角达到151.6°,滚动角接近0°.通过扫描电子显微镜(SEM)观察涂层表面的微观结构,发现超疏水性的涂层具备微-纳复合阶层结构,类球状突起粒径在5μm左右,类球状突起上分布纳米团聚颗粒,直径约为50 nm.这种类似荷叶表面的微(纳复合阶层结构,结合硅树脂的低表面能,使得复合涂层具备了超疏水性能.     

Progress towards fully spray-coated semitransparent inverted organic solar cells with a silver nanowire electrode

We demonstrated a fully spray-coated semitransparent organic solar cell, from the lowermost organic layer to the uppermost top electrode. The fabricated devices based on a poly (3-hexylthiophene):[6,6]-phenyl-C61 butyric acid methyl ester (P3HT:PCBM) are semitransparent (∼70% transparency at long wavelength beyond 650 nm), fully spray-coated from organic layer to top electrode, highly efficient (∼80% of that of a device with a conventional metal electrode).