Poly(dopamine) assisted epoxy functionalization of hexagonal boron nitride for enhancement of epoxy resin anticorrosion performance

Hexagonal boron nitride (h‐BN) is modified by a simple and green method based on self‐oxidation of dopamine and epoxy groups functionalized silane (KH560) grafting. The surface modification and microstructure of h‐BN are characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The poly(dopamine) and epoxy groups not only increase the compatibility of the h‐BN and enhance its interaction with epoxy matrix but also exhibit a remarkable superiority in enhancing the anticorrosion performance of epoxy coatings. In addition, the anticorrosion mechanisms of h‐BN@PDA‐KH560 are tentatively discussed. Copyright © 2016 John Wiley & Sons, Ltd.     

苯并噻唑(啉)类润滑油添加剂的研究进展

苯并噻唑(啉)类添加剂是一类具有良好摩擦学性能、抗氧抗腐性能的环境友好型润滑油添加剂。本文对其摩擦学性能、抗氧抗腐性能和复配性能等方面做了系统评述,并对其研究和应用方面的问题作了初步总结,期望能够为苯并噻唑(啉)类润滑油添加剂的实际应用起到一定的指导作用。     

A Prussian-Blue Bifunctional Interface Membrane for Enhanced Flexible Al–Air Batteries

Flexible Al–air batteries have attracted widespread attention in the field of wearable power due to the high theoretical energy density of Al metal. However, the efficiency degradation and anodizing retardation caused by Al parasitic corrosion severely limit the performance breakthrough of the batteries. Herein, a Prussian-blue bifunctional interface membrane is proposed to improving the discharge performance of hydrogel-based Al–air battery. When a rational 12 mg·cm⁻² membrane is loaded, the effect of anticorrosion and activation is optimal thanks to the formation of a stable and breathable interface. The results demonstrate that a flexible Al–air battery using the membrane can output a high power density of 65.76 mW·cm⁻². Besides, the battery can achieve a high capacity of 2377.43 mAh·g⁻¹, anode efficiency of 79.78%, and energy density of 3176.39 Wh·kg⁻¹ at 10 mA·cm⁻². Density functional theory calculations uncover the anticorrosion-activation mechanism that Fe³⁺ with a large number of empty orbitals can accelerate electrons transfer, and nucleophilic reactant [Fe^II(CN)₆]⁴⁻ promotes the Al³⁺ diffusion. These findings are beneficial to the inhibition of interfacial parasitic corrosion and weakening of discharge hysteresis for flexible Al–air batteries.     

Fabrication of Fe3O4@SiO2 nanocomposites to enhance anticorrosion performance of epoxy coatings

SiO₂‐coated Fe₃O₄ (Fe₃O₄@SiO₂) nanocomposites were prepared by sol–gel method, and the anticorrosion performance of composite coatings was discussed. The structure of the Fe₃O₄@SiO₂ nanocomposites was verified through Fourier transform infrared, X‐ray diffraction, and scanning electron microscopy. Composite epoxy coatings with same concentrations of Fe₃O₄ and Fe₃O₄@SiO₂ were measured by scanning electron microscopy contact angle meter. More importantly, the Fe₃O₄@SiO₂ nanocomposites not only obtained a homogeneous dispersion and compatibility in epoxy resin but also exhibited an obvious superiority in enhancing the anticorrosion performance of epoxy coatings. Furthermore, the anticorrosion mechanism of Fe₃O₄@SiO₂/epoxy composite coating was tentatively discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

Poly(aryl ether) bearing electroactive tetraaniline pendants and allyl groups: Synthesis,photo‐crosslinking and electrochemical properties

We describe the synthesis of a novel electroactive photo‐crosslinkable poly(aryl ether), containing tetraaniline pendants and allyl groups (EPPAE). The polymer structure and spectral properties are studied in detail. By introducing the electroactive tetraaniline pandents, EPPAE reveals reversible electrochemical activity, expected electrochromic behavior and good anticorrosive performance. After crosslinking the allyl groups with UV exposure, the resultant polymer (c‐EPPAE) shows drastic change in electrochemical properties. The c‐EPPAE/ITO electrode exhibits declining electroactivity but excellent electrochemical stability, which are associated with densification of the electroactive layer. Furthermore, in the corrosive protection measurements, c‐EPPAE reveals an outstanding protection efficiency (99.92%) for stainless steel substrates. A comprehensive study of electrochromic properties and corrosive protection of EPPAE before and after UV exposure will provide an insightful tool for the developing electrochromic smart windows, electrochromic displays, and anticorrosive paint. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2321–2330     

Reinforcement of phosphorylated graphene oxide on the anticorrosive properties of waterborne acrylate-epoxy resin coatings

Abstract

Phosphorylated graphene oxide (PedGO) was synthesized through the in-situ phosphate esterification method with urea as catalyst and then embed into waterborne acrylate-epoxy resin emulsion (AE) coating to modify the coating. The TEM and AFM indicated that phosphate was uniformly decorated on GO sheets, forming a large phosphorylated graphene oxide sheets. The PedGO improved the water vapor permeability and the coating adhesion strength after 30?days of immersion in 3.5% NaCl of AE coatings, respectively. Electrochemical impedance spectroscopy measurements (EIS) revealed that the PedGO-modified AE (PedGO/AE) was an outstanding barrier against corrosive media compared with AE or GO-modified AE (GO/AE). Scratch tests also showed that the corrosion-promotion effect of PedGO in AE was inhibited. The enhanced corrosion protection performance was observed because on the one hand the PedGO can greatly prolonged the diffusion pathway of corrosive media in the coating matrix; on the other hand the organic phosphate on the PedGO formed the passivation membrane with metal ions by chelation in the corrosion region, which can prevented the contact of corrosive medium and metal.     

Acrylate based anticorrosion films using novel bis‐phosphonic methacrylates

Two novel phosphonated methacrylate monomers were successfully synthesized and subsequently incorportated into adhesion/anticorrosive coatings. Specifically, they were propyl N,N‐tetramethyl‐bis(phosphonate)‐2‐hydroxyl‐bis(methylene) amine methylmethacrylate (MAC₃NP₂) and 2‐[2,2‐bis(diisopropoxyphosphoryl)ethoxy]‐methylmethacrylate, (MAC₃P₂). The phosphonic forms of each monomer were blended with ～85% w.w acrylates (tripropyleneglycol‐diacrylate and hexanediol‐diacrylate) and 6% w.w of the photo sensitive initiator Darocur®. Along with a monophosphonic monomer synthesized in a previous publication (MAC₃P), they were polymerized on Q‐panels under ultraviolet light, and then subject to the salt spray test (ca. 0.5 mol/L NaCl at 35 °C) for a duration of up to 50 days. The results indicate that acrylate blends with low concentration of the bisphosphonic compound MAC₃P₂ have excellent resistance to corrosion, thus excellent adhesive properties. Importantly, these coatings were formed without the use of a hydrophobic polymer matrix or solvents. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7972–7984, 2008     

Self‐Healing and Antifouling Multifunctional Coatings Based on pH and Sulfide Ion Sensitive Nanocontainers

Application of mesoporous silica nanoparticles (MSNs) as delivery tools for self‐healing coatings is limited by spontaneous leakage and specifically responsive release of small molecular inhibitors. In this work, a pH/sulfide ion responsive release system based on MSNs using a Cu‐BTA complex forms at the openings of the mesopores into which BTA (corrosion inhibitor) and benzalkonium chloride (biocide) are loaded. The spontaneous leakage of active species is completely avoided and premature release of the loaded composition was lowered to 0.02. The responsive release begins when the pH is lower than 5 or [S^2?] is higher than 0.02 mM (about 0.6 ppm). The hybrid coating containing the responsive release system exhibits feedback self‐healing property sensitive to lowering of pH and sulfide ion concentration and, at the same time, provides a high barrier level for a long time. Due to incorporation of biocide in the release system, the coating is also provided with antifouling properties.     

Anticorrosive Copper Current Collector Passivated by Self-Assembled Porous Membrane for Highly Stable Lithium Metal Batteries

The regulation of lithium plating/stripping behavior is considered to be critical for next-generation safe and high-energy-density lithium metal batteries. Lithium deposition with maximum granular size and minimum microstructural tortuosity can significantly improve the lithium plating/stripping efficiency. Here, a self-assembled organosilane layer with nanopores is constructed on Cu current collector surface via a thiol-Cu reaction. In contrast to typical stacked-particle morphology with small grain size and high specific area in ether electrolyte, dough-like and lateral-growth lithium deposition can be plated on the modified Cu current collector due to the low surface energy of a lithiophilic Si O Si membrane. The planar and dense lithium deposition contributes to the stable implementation of up to near 500 cycles in full cells with high-loading LiFePO₄ cathode. Anticorrosion in rigorous Cl-ion containing solution can even be achieved due to the corrosive repellency of hydrophobic organosilane. A high Coulombic efficiency (97.12%) is remained after corroding for 300 min. Moreover, the irreversible capacity loss caused by galvanic corrosion, an ignored but crucial aspect, has been significantly suppressed due to the passivation of high-redox-potential Cu by organosilane coating.     

工业级碱性海水电解:近期进展和展望

由太阳能、风能和海洋等可再生能源驱动的工业级水分解产氢为能源和环境的可持续性发展开辟了一条极具潜力的道路。然而,在工业上最先进电解技术使用高纯水作为氢源,这将带来严重的淡水资源危机。海水分解为饮用水短缺提供了一条切实可行的解决途径,但仍面临规模工业化生产的巨大挑战。在这里,我们总结了海水分解的最新进展,包括反应机制、电极设计标准和直接海水分解的工业电解槽。深入讨论了应对海水电解中的关键挑战,如活性位点、反应选择性、耐腐蚀性和传质能力等的解决方案。此外,该文章重点总结了海水电解设备的最新发展,并提出了设计长寿命直接海水电解装置的有效策略。最后,我们对直接海水电解的未来机遇和挑战提出了自己的观点。