A Brief Communication on the Improved Mechanism of Graphene on Zinc-Rich Coatings
A Brief Communication on the Improved Mechanism of Graphene on Zinc-Rich Coatings
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DOI：
10.20964/2019.04.26
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发表时间：
2019-04
影响因子：
1.5
通讯作者：
Xiao Wang;Si Chen;Rui Ding;Nan Zhou;Yan Zheng;Hai-bin Yu;Bing-jun Li;T. Gui;Weihua Li
中科院分区：
文献类型：
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作者：
Xiao Wang;Si Chen;Rui Ding;Nan Zhou;Yan Zheng;Hai-bin Yu;Bing-jun Li;T. Gui;Weihua Li
为了实现石墨烯在环氧树脂中的高效分散，以五倍子的天然提取物为原料合成了没食子酸型环氧树脂单体。在石墨烯/没食子酸基环氧树脂单体分散体系的基础上，进一步制备了石墨烯富锌防腐涂料。通过电化学实验和光谱表征，研究了石墨烯对富锌涂层的影响及其作用机理。实验表明，石墨烯提高了富锌涂层的阴极保护电流，延长了阴极保护时间。同时，石墨烯减缓了腐蚀性介质对涂层的渗透。石墨烯的导电性改善了锌颗粒以及锌和铁之间的电接触，并将未活化的锌颗粒转化为活性锌颗粒。石墨烯的分散和层状结构延长了腐蚀介质的渗透路径，从而降低了涂层的渗透速率和水分含量。微区拉曼光谱对锌腐蚀产物的跟踪证实了这一点。
Gallic acid-based epoxy resin monomer was synthesized by the natural extract of gallnut for the efficient dispersion of graphene in epoxy resin. The graphene zinc-rich anticorrosion coatings were further prepared on the basis of the graphene / gallic acid-based epoxy resin monomer dispersion system. Electrochemical experiments and spectral characterization were carried out to study the effect of graphene on zinc-rich coatings and its mechanism. Experiments showed that graphene enhanced the cathodic protection currents of the zinc-rich coatings and prolonged the cathodic protection time. Simultaneously, graphene slowed down the penetration of corrosive media into the coatings. The conductivity of graphene improved electrical contact between zinc particles as well as zinc and iron, and transformed un-activated zinc particles into activated zinc particles. The dispersed and layered structure of the graphene extended the permeation path of the corrosive medium, which resulted in reduced permeation rate and decreased water content of the coatings. It was demonstrated by the tracking of zinc corrosion products by micro-area Raman spectroscopy.