Mechanism Study On The Effect Of CNT On The Mechanical Properties Of Graphene/Epoxy Composite System

CNT and graphene have excellent mechanical,thermal and electrical properties.They are widely used in the preparation and performance study of carbon nanocomposites.However,there is a large difference in their structure,and the CNT presents a one-dimensional tube,while the graphene presents a two-dimensional sheet.In this paper,CNT and graphene are used in epoxy resin by using the characteristics of the two structures.The effect of the composite configuration on the mechanical properties of the composites was investigated.Based on the analysis of the microstructure of the composite,the mechanism of the influence of CNT and graphene on the mechanical properties of the nanocomposites was determined.Materials Studio software was used in this study,taking CNTs,graphene and epoxy resin as research objects,different CNTs/graphene/epoxy resin model systems were constructed by changing the length,radius,wall number and the angle and distance between CNT and graphene.The tensile and graphene pullout simulation of composite material model is carried out by script,and the influence factors on the tensile properties and interfacial bonding properties of composites are studied.According to the uniaxial tensile composite material are simulated,between the length of CNT and CNT with the increase of the distance graphene are able to form more epoxy resin adsorption layer,so the young's modulus of nanocomposites of CNT in axial direction is increased;and through the analysis of stress-strain curves of composite material in the process of CNT on the radial configuration diagram,the composite failure mainly by the separation of epoxy resin matrix and graphene surface.The adsorption layer of epoxy resin between CNT and graphene has the function of connecting them.Therefore,the larger the distance between them is,the more the molecular chains of the adsorption layer are,the better the tensile mechanical properties of composite materials in the radial direction of CNT.Through the study of the interfacial bonding properties of graphene,the addition of CNT can enhance the interfacial bonding properties of graphene in the composites.The interaction between CNT and graphene is directly proportional to the length of carbon nanotubes,while the combined angle between CNT and graphene does not change the initial binding energy of graphene.However,the interfacial bonding properties of graphene are affected by the difference of the contact part between the CNT and graphene during the pull-out process.The interfacial bonding properties of graphene can be enhanced by increasing the radius of CNT,the number of walls and the reduction of the distance between CNT and graphene.By analyzing the interfacial adhesion energy of graphene,it is found that the interfacial adhesion of graphene first increases and then decreases.However,increasing the radius of CNT and the number of walls can increase the interfacial adhesion energy in the pull out process of graphene.