First Principles Calculation And Experimental Study Of Graphene Modified AF/POM Composite Interface

The composite materials of Interpenetrating network structure is a new research direction in the field of materials.Metal and polymer are intertwined and interpenetrated,forming a penetrating network structure.Both of the phases of the composite are matrix and enhanced phase.The formation of the network structure of metal in the polymer can greatly improve the thermal conductivity of material.At the same time,the interface bonding between material elements is an important factor affecting the comprehensive properties of the composite.In this paper,the effects of different interface treatments on the tribological properties and thermal conductivity of AF/POM composites were investigated.On the basis of the experiment,the mechanism of the interface binding of graphene to improve the interface of the composite was simulated.The adsorption types and bonding modes of atoms are studied in detail.In this paper,the surface of aluminum foam was treated with graphene dispersions first.And then the three-dimensional interpenetrating composites of foamed AF/POM were prepared by injection molding process.The thermal conductivity and friction and wear properties of the composites were studied.Fourier Infrared Spectroscopy(FT-IR),X ray diffractometer(XRD),Energy spectrometer(EDS)and Scanning Election Microscope(SEM)were employed to characterize the composite.The results show that the interfacial bonding strength of the composites treated with graphene is significantly higher than that of the untreated and NaOH treated.Graphene can effectively improve the interface bonding between aluminum and plastic.The thermal conductivity of AF/POM interpenetrating composites treated with graphene is much higher than that of untreated.The friction coefficient and wear volume of composite material modified by graphene is much lower than that of untreated.The treatment temperature of graphene/AF has an effect on the thermal conductivity,but little significance for improving the friction and wear properties.The bonding behavior of the interface between graphene and the composites was studied by first principle calculation method.The reaction mechanism and characteristics of the interfacial modification were analyzed from the atomic and electronic scales.The interaction between graphene different oxygen functional groups and boundary structures on the surface of aluminum and POM molecular chain was systematically studied.The results show that the O and C on different structures of the surface of graphene have obvious bonding with aluminum.The difficulty degree of adsorption is:the Gr boundary>Gr=O>Gr-OH>Gr-COOH>Gr.Graphene adsorbed on Al surface steadily,making the graphene can exist as aluminum interface transition layer stability.It is known from the calculation results that the C of graphene boundary is mainly covalent with Al,which is chemisorption.O and Al are mainly covalent interaction between covalent and ionic bonds,which is physical adsorption.The physical adsorption strength Gr=O>Gr-OH>Gr-COOH>Gr boundary>Gr.The interaction of graphene boundary on POM is not obvious,but is strong on Al surface.The interaction between the graphene boundary and the A1 and POM shows the opposite characteristics.