Preparation And Properties Of Nano-fluid-like Modified Carbon Fiber Reinforced Resin Matrix Composites

In recent years,carbon fiber composites(CFRP)have been widely used in industry,medical equipments,aerospace and other fields because of their excellent mechanical properties.But their poor thermal conductivity limits their wider application.Adding thermally conductive nano-filler graphene oxide/iron trioxide(GO@Fe₃O₄)to the sizing agent is an effective method,which can enhance the thermal conductivity and mechanical properties of CFRP.However,the problem of nanoparticle agglomeration has not been solved.In this paper,the dispersion of GO@Fe₃O₄ in water-based sizing agent was solved by modifying GO@Fe₃O₄,and the mechanical properties and thermal conductivity of CFRP were better improved.In this paper,GO@Fe₃O₄ was modified by silane coupling agent-polyether ammonia(KH560-M2070),and solvent-free GO@Fe₃O₄ nanofluids were successfully prepared.The solvent-free GO@Fe₃O₄ nanofluids were verified by fourier infrared spectrometer,X-ray diffraction,modulus-temperature curve test,thermal gravimetric analysis,etc.The good dispersion and stability of solvent-free GO@Fe₃O₄ nanofluid in water were confirmed by UV-vis spectrophotometer and microscope,which laid a foundation for its modification of water-based epoxy sizing agent.The experimental results show that the content of GO@Fe₃O₄ nanoparticles in solvent-free GO@Fe₃O₄nanofluid is 14%,and the dispersion and stability of solvent-free GO@Fe₃O₄nanofluid in water are far better than GO@Fe₃O₄ nanoparticles.Taking advantage of good dispersion of the solvent-free GO@Fe₃O₄ nanofluids in water,the solvent-free GO@Fe₃O₄ nanofluids were doped into waterborne epoxy sizing agents with different contents.The carbon fiber reinforced epoxy resin composites were prepared after sizing by hybrid sizing agent,and the mechanical properties and thermal conductivity of the composites were tested.After treatment,the surface of carbon fiber became rough,and it can be clearly seen that nano-sheets form continuous paths on the surface of carbon fiber.The results showed that when the content of solvent-free GO@Fe₃O₄ nanofluids is 2.5%,the maximum thermal conductivity reached 3.099 W/mK,the inter-laminar shear strength increased to 64.01MPa,and the flexural strength increased to 1161.1Mpa.In this paper,magnetic field is also used to explore the positive influence of the orientation of solvent-free GO@Fe₃O₄ magnetic nanofluid in hybrid sizing agent on carbon fiber composites.In the sizing process,the solvent-free GO@Fe₃O₄ magnetic nanofluid was oriented in magnetic field to prepare carbon fiber reinforced epoxy resin composites.The mechanical properties and thermal conductivity of the composites were tested and compared with different carbon fiber composites.The nanosheet orientation can be clearly seen on the carbon fiber surface under magnetic field,and the overall performance of the composite system is further improved.When the content of the oriented solvent-free GO@Fe₃O₄ nanofluid is 2.5%,the maximum thermal conductivity reaches 3.473 W/mK,and the shear strength and bending strength increase to 71.36MPa and 1224.6MPa respectively.From the above experimental results,the effects of solvent-free GO@Fe₃O₄magnetic nanofluid modified waterborne epoxy sizing agent on the properties of composites were researched,which provided a new idea for the industrial preparation and application development of modified carbon fibers.