氢键对氧化石墨烯复合结构层间剪切行为影响研究

针对氧化石墨烯层状复合结构性能优化设计要求及其对环境湿度的高敏感性,开展了氧化石墨烯在湿润环境下的层间剪切行为研究.首先,采用连续力学理论,获取不同氧化浓度时氧化石墨烯层状结构层间粘结能、层间氢键相互作用能及剪切应力表达式;所获得的层间能量理论值与分子动力学模拟结果基本一致.其次,通过在氧化石墨烯层间加入不同含量水分子...

Effect of Hydrogen Bond on Interlayer Shear Behaviors of Graphene Oxides

According to the optimization design of graphene oxide (GO) layered composites and their high sensitivity to environmental humidity, the interlayer shear behaviors of GO in humid environment have been studied. Firstly, expressions of interlayer cohesive energy, interlayer hydrogen bond (HBond) interaction and shear stress have been obtained by employing theoretical models. Good agreements can be achieved for the results obtained by theoretical models and molecular dynamics simulations. Different numbers of water molecules have been further introduced into the interlayer of GO structures. Then, interfacial properties of GO composites can be improved by adjusting oxidation concentrations and contents of interlayer water molecules, which determine the interlayer HBonds networks. The results show that increasing the oxidation concentration can effectively increase the density of the interlayer HBonds networks, thus improving the interlayer shear strength of GO structures. However, an optimal oxidation concentration can be obtained for GO structures with limited sizes, where enhancement of shear stress of GO will reach saturation. In this situation, introducing water molecules into interlayers of GO structures can further enhance their shear strength, and an optimal content of water molecules has also been observed. The research put forward a simple numerical method to evaluate HBond energy and propose two ways to improve the mechanical properties of GO layered composites. During these processes, the effect of HBonds networks on interlayer shear properties of GO composites has been highlighted. This study should be of great importance to providing a significant theoretical support for designing GO-based composites.