The surface functionalization of graphene oxide (GO) is always attractive in modulating the interfacial characteristics, improving the interfacial bonds and mechanical properties of epoxy-based nanocomposites. In this contribution, amine functionalized graphene oxide (AGO) samples were prepared through the surface functionalization of GO using m-xylylenediamine (m-XDA) and polyetheramine D230, respectively. Simultaneously, weakly oxidized and normally oxidized GO samples were both functionalized to obtain AGO samples with low and high amine grafting density. AGO/epoxy nanocomposites were fabricated and their mechanical properties at room temperature (RT) and liquid nitrogen temperature (LNT) were investigated. Interfacial characteristics of the nanocomposites were revealed through experimental and molecular dynamic (MD) simulation methods. It was found that m-XDA grafted GO (MAGO) showed better dispersion in the matrix and prominently higher efficiency in enhancing the mechanical properties of epoxy resin than D230 grafted GO (DAGO). MAGO nanocomposites exhibited tensile strength 18.1% and 11.3% higher than neat epoxy at RT and LNT, respectively. The result was highly consistent with the enhanced interfacial interaction energy between MAGO and epoxy compared to that between DAGO and epoxy as revealed by MD simulation. However, nanocomposites modified by AGO with improved amine grafting density didn’t show enhanced mechanical properties as expected from MD simulation.

氧化石墨烯（GO）的表面功能化在调节界面特性，改善界面键和环氧基纳米复合材料的机械性能方面一直很有吸引力。在这一贡献中，分别使用间苯二甲胺（m-XDA）和聚醚胺D230通过GO的表面官能化制备了胺官能化的氧化石墨烯（AGO）样品。同时，将弱氧化和正常氧化的GO样品均官能化，以得到具有低和高胺接枝密度的AGO样品。制备了AGO /环氧纳米复合材料，研究了它们在室温（RT）和液氮温度（LNT）下的力学性能。通过实验和分子动力学（MD）模拟方法揭示了纳米复合材料的界面特征。已发现，与D230接枝的GO（DAGO）相比，m-XDA接枝的GO（MAGO）在基质中表现出更好的分散性，并且在增强环氧树脂的机械性能方面显着更高的效率。MAGO纳米复合材料在RT和LNT上的拉伸强度分别比纯环氧树脂高18.1％和11.3％。MD模拟显示，与DAGO和环氧树脂之间的界面相互作用能相比，MAGO和环氧树脂之间的界面相互作用能提高了，这一结果高度一致。然而，由AGO改性的具有提高的胺接枝密度的纳米复合材料并未显示出MD模拟所预期的增强的机械性能。MAGO纳米复合材料在RT和LNT上的拉伸强度分别比纯环氧树脂高18.1％和11.3％。MD模拟显示，与DAGO和环氧树脂之间的界面相互作用能相比，MAGO和环氧树脂之间的界面相互作用能提高了，这一结果高度一致。但是，由AGO改性的具有提高的胺接枝密度的纳米复合材料并未显示出MD模拟所预期的增强的机械性能。MAGO纳米复合材料在RT和LNT上的拉伸强度分别比纯环氧树脂高18.1％和11.3％。MD模拟显示，与DAGO和环氧树脂之间的界面相互作用能相比，MAGO和环氧树脂之间的界面相互作用能提高了，这一结果高度一致。然而，由AGO改性的具有提高的胺接枝密度的纳米复合材料并未显示出MD模拟所预期的增强的机械性能。