Abstract Corrosion resistance of waterborne epoxy (WEP) coatings can be enhanced by the addition of graphene sheets as the physical barriers. The dispersion of graphene sheets in the WEP matrix is one of the key issues. Here, silane coupling agent was introduced in polyetheramine functionalization of graphene oxide as the molecular bridge via a two-step modification. Firstly, hydrolyzed silane was reacted with the hydroxyl groups of graphene oxide. Then, polyetheramine was grafted on the silanized graphene oxide, producing D-SGO. A long molecular tail with amino end groups was introduced on graphene surfaces, enhancing the steric hindrance, the compatibility with epoxy curing agent, as well as the interfacial bonding with WEP matrix. The interlayer spacing between polyetheramine-functionalized graphene oxide layers was increased from 1.13 nm to 1.77 nm by the silane-bridging. The molecular structure of D-SGO was analyzed by chemical characterization and molecular dynamics simulations. The two-step modification not only increased the length of the grafted molecules, but changed the reaction sites from the carboxyl groups at the graphene edges/defects to the hydroxyl groups on the basal plane. The insert of silane-bridging improved the dispersion of D-SGO. According to impedance measurements, the modulus of D-SGO0.2%/WEP was kept at 5 × 109 Ω cm2 for 4 months. The superior anticorrosion performance benefited from the barrier properties of well-dispersed D-SGO and the enhanced interfacial bonding between D-SGO and the WEP matrix.

中文翻译：

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硅烷桥联对聚醚胺官能化氧化石墨烯在水性环氧复合材料中分散的影响

摘要 通过添加石墨烯片作为物理屏障，可以提高水性环氧 (WEP) 涂料的耐腐蚀性。石墨烯片在 WEP 矩阵中的分散是关键问题之一。在这里，通过两步改性将硅烷偶联剂引入氧化石墨烯的聚醚胺官能化中作为分子桥。首先，水解硅烷与氧化石墨烯的羟基反应。然后，聚醚胺接枝在硅烷化的氧化石墨烯上，产生 D-SGO。在石墨烯表面引入了具有氨基端基的长分子尾，增强了空间位阻、与环氧树脂固化剂的相容性以及与 WEP 基质的界面结合。聚醚胺功能化氧化石墨烯层之间的层间距从 1.13 nm 增加到 1。77 nm 由硅烷桥接。通过化学表征和分子动力学模拟分析了 D-SGO 的分子结构。两步改性不仅增加了接枝分子的长度，而且将反应位点从石墨烯边缘/缺陷处的羧基改变为基面上的羟基。硅烷桥接的插入提高了 D-SGO 的分散性。根据阻抗测量，D-SGO0.2%/WEP 的模量保持在 5 × 109 Ω cm2 4 个月。优异的防腐性能得益于分散良好的 D-SGO 的阻隔性能以及 D-SGO 与 WEP 基体之间增强的界面结合。两步改性不仅增加了接枝分子的长度，而且将反应位点从石墨烯边缘/缺陷处的羧基改变为基面上的羟基。硅烷桥接的插入提高了 D-SGO 的分散性。根据阻抗测量，D-SGO0.2%/WEP 的模量保持在 5 × 109 Ω cm2 4 个月。优异的防腐性能得益于分散良好的 D-SGO 的阻隔性能以及 D-SGO 与 WEP 基体之间增强的界面结合。两步改性不仅增加了接枝分子的长度，而且将反应位点从石墨烯边缘/缺陷处的羧基改变为基面上的羟基。硅烷桥接的插入提高了 D-SGO 的分散性。根据阻抗测量，D-SGO0.2%/WEP 的模量保持在 5 × 109 Ω cm2 4 个月。优异的防腐性能得益于分散良好的 D-SGO 的阻隔性能以及 D-SGO 与 WEP 基体之间增强的界面结合。2%/WEP 保持在 5 × 109 Ω cm2 4 个月。优异的防腐性能得益于分散良好的 D-SGO 的阻隔性能以及 D-SGO 与 WEP 基体之间增强的界面结合。2%/WEP 保持在 5 × 109 Ω cm2 4 个月。优异的防腐性能得益于分散良好的 D-SGO 的阻隔性能以及 D-SGO 与 WEP 基体之间增强的界面结合。