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[Display omitted] • TGO nanosheets with emergency response closure function were fabricated. • The appropriate amount of TGO could improve the corrosion resistance of vinyl ester resin. • TGO significantly improved the barrier capacity of the broken composite coating. Vinyl ester resins (VER) are commonly used in the field of anticorrosive coatings. During the preparation and application of the coatings, it is inevitable to produce defects such as micro-porosity, micro-cracks, and scratches, which will reduce the barrier capacity of the anticorrosive coatings against corrosive media. In this paper, 2-(chloromethyl) pyridine is used to functionalize the silane-decorated graphene oxide for obtaining the functionalized modified graphene oxide (TGO). The aggregation of TGO nanosheets under the influence of Fe2+ ions generated by corrosion, achieving the response closure of TGO/VER coatings to hinder the diffusion path of corrosive media, thereby strengthening the anticorrosion effect of the coating. The water vapor transmission rate of TGO/VER coatings decreases significantly after immersion in Fe2+ solution. Electrochemical impedance spectroscopy tests indicate that TGO/VER coatings have better corrosion resistance compared with VER coatings, in which the impedance modulus after immersion for 100 d of 0.3TGO/VER coatings (3.93 × 1010 Ω cm2) is about four orders of magnitude greater than that of the VER coatings (5.85 × 106 Ω cm2). The TGO/VER coatings provide the responsive closure function via complexation of TGO with Fe2+ to achieve the long-term corrosion resistance. These results suggest that TGO/VER system provides an effective strategy for the preparation and application of graphene-based long-term anticorrosive coatings. [ABSTRACT FROM AUTHOR]

• Oxidized graphene was modified by lignin and pyridine derivatives. • Inspired by mimosa, a long-term anti-corrosion composite coating was prepared. • Pyridine group and Fe2+ had a strong binding energy (-369.99 kcal/mol). Although the coating can effectively prevent metal corrosion, it is easy to form micro-pores and micro-cracks during the curing process, and the coating is inevitably damaged by the external environment during use, resulting in a reduction in its protective ability, thereby shortening the service life of the substrate. Inspired by the stress closure function of mimosa, an intelligent anti-corrosion coating with stress closure function against corrosion products (Fe2+) was prepared by using pyridine derivatives and lignin grafted graphene oxide (ATGO). By density functional theory calculation, the binding energy of pyridine group and Fe2+ was −369.99 kcal/mol, and their strong complexation would facilitate the formation of a dense protective layer at the metal corrosion interface. The test results showed that ATGO-CM coating had high fracture strength (86.9 MPa) and adhesion strength (2.03 MPa), as well as low water vapor permeability (1.3 × 10-6 g m−1 day−1 Pa−1). Electrochemical testing denoted that after soaking in 3.5 wt% saline solution for 100 days, the impedance modulus of the ATGO-CM coating remained at 5.36 × 109 Ω·cm2 at low frequencies (f = 0.01 Hz), which was two orders of magnitude higher than the blank group. Through scratch experiments showed that the complexation effect of pyridine groups and corrosive products could significantly improve the corrosion resistance of the coating, with R ct value of 1.8 × 104 Ω cm2 for the damaged coating, one order of magnitude higher than the blank group. This work not only provided a reference for the preparation of intelligent anti-corrosion coatings with bionic functions, but also increased the added value of biomass materials. [ABSTRACT FROM AUTHOR]

Abstract: In this work, CuPt nanocomposites were decorated on ionic-liquid-assisted graphene and their electrocatalytic activities for methanol oxidation were investigated. The procedure involved the synthesis of graphene by electro-oxidation of pure graphite in an ionic-liquid/water solution, followed by the deposition of Cu nanoparticles on graphene and their further reduction of chloroplatinic acid. The catalysts were characterized by using transmission electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, Raman spectroscopy and X-ray diffraction. Subsequently, electrocatalytic activities of this catalyst for methanol oxidation were measured by cyclic voltammetry, chronoamperometry and CO-stripping voltammetry. Results showed that the electrocatalytic activity and stability of CuPt/ionic-liquid-assisted graphene for methanol oxidation was better than that on commercial carbon blacks, which was attributed to the increase of the graphene conductivity by ionic liquid and the facile removal of intermediate poisoning species with the aid of Cu, demonstrating that ionic-liquid-assisted graphene can be an alternative support for Pt immobilization in direct methanol fuel cells. [Copyright &y& Elsevier]