Research On Fabrication And Mechanical Properties Of Graphene Fiber Reinforced Aerogel Materials

Graphene is a kind of unique two-dimensional carbon nanomaterials.It has excellent electrical,thermal and mechanical properties,which make it have broad application prospects.Related research work such as one-dimensional graphene nanometers,two-dimensional graphene films and three-dimensional graphene aerogels make graphene materials more functional due to their respective characteristics.The research of graphene fibers is one of the hot spots in the field of graphene and the difficulty in the research of graphene fibers lies in how to convert the graphene sheets material into a good fiber-like macroscopic assembly materials and take into account to its mechanical properties.However,wet-spinning provides a possibility for continuous preparation of graphene fibers.Although some progress has been made in the research of graphene fibers based on wet-spinning,there are still some shortcomings in the continuous preparation of fibers and follow-up application.In this paper,some improvements have been made based on the existing research,and a new method to enhance aerogels has been proposed.In this paper,dimethylformamide(DMF)is used as solvent of graphene oxide(GO)solution and ethyl acetate is used as coagulation bath for wet-spinning.GO fibers prepared by DMF solvent and ethyl acetate can not only improve the mechanical strength of the fibers,but also facilitate the continuous preparation of graphene fibers.GO was prepared by improved Hummers method and a series of characterization was conducted to verify the successful preparation of large-scale GO.The dispersion of GO in different solvents was studied.GO fibers were prepared by wet-spinning in water system and organic system,and a series of characterization tests were carried out,and continuous spinning equipment was built.The effects of the concentration of GO,the type of coagulation bath and the inner diameter of spinneret on the surface morphology,microstructure and mechanical properties of GO fibers were investigated.The GO fibers were mainly optimized by regulating the concentration of spinning solution and the inner diameter of spinneret.The graphene fibers with tensile strength and elastic modulus up to 821.7 MPa and 73.7 GPa,which were prepared by high temperature reduction.The research effort has focused on fabricating fibers,and GO fibers membrane was prepared.The method of strengthening graphene aerogels through GO fibers was innovatively proposed.Ultimately,GO fibers prepared by wet-spinning was mixed with GO solution as precursor to prepare the fiber reinforced aerogel with tensile strength of 177.5 MPa.The flexural and tensile properties of aerogel were significantly enhanced.