摘要
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和改变氧化浓度,调控层间氢键网络密度,以改善氧化石墨烯复合结构的界面力学性能.研究结果表明,增加氧化浓度有效增加了层间氢键网络密度,从而提高了氧化石墨烯层间剪切强度.但当氧化石墨烯为有限尺寸时,氧化浓度存在最佳值,在达到该值后氧化石墨烯剪切强度将基本保持不变.此时,在氧化石墨烯层间再引入水分子可进一步增强其剪切强度,且含水量亦存在最佳值.总之,该研究提出了一种氢键能量的简便数值计算方法,阐述了层间氢键网络密度对氧化石墨烯复合结构层间剪切性能影响的机理,并提出两种提升其层间力学性能的途径,为氧化石墨烯基复合结构性能优化设计提供了一定的参考.
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 a humid environment have been studied.Firstly,the expressions of interlayer cohesive energy,interlayer hydrogen bonding interaction and shear stress have been obtained by employing theoretical models.Good agreement can be achieved between 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,the interfacial properties of GO composites can be improved by adjusting oxidation concentrations and contents of interlayer water molecules,which determine the interlayer hydrogen bond(HBond)networks.The results show that increasing the oxidation concentration can effectively increase the density of the interlayer HBond 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 the enhancement of shear stress of GO will reach saturation.In this situation,introducing water molecules into the interlayers of GO structures can further enhance their shear strength,and an optimal content of water molecules has also been observed.The research puts forward a simple numerical method for evaluating the HBond energy and proposes two ways to improve the mechanical properties of GO layered composites.During these processes,the effect of HBond networks on interlayer shear properties of GO composites has been highlighted.This study should be of great importance for providing a significant theoretical support for the design of GO-based composites.
作者
刘俊
董淑宏
赵军华
Jun Liu;Shuhong Dong;Junhua Zhao(Jiang Su Key Laboratory of Advanced Food Manufacturing Equipment and Technology,School of Mechanical Engineering,Jiangnan University,Wuxi,214122)
出处
《固体力学学报》
CSCD
北大核心
2021年第4期443-454,共12页
Chinese Journal of Solid Mechanics
基金
国家自然科学基金(11602096,11972171)
纳智能材料器件教育部重点实验室开放课题基金项目(NJ2020003)资助。
关键词
氧化石墨烯
剪切行为
氢键
氧化浓度
水分子
graphene oxide
shear behavior
hydrogen bond
oxidation concentration
water molecule
