Investigation On Electrospinning Preparation And Properties Of PAN-based Carbon Nanofibers

Electrospinning is the common method to obtain continuous carbon nanofibers.The carbon nanofibers have the advantages of stable structure and film-forming property.Polyacrylonitrile-based carbon nanofibers are with large amounts of micropores during the preparation process.Currently,the carbon nanofibers show low mechanical performance due to the micropores structural defects.The mechanical properties can be improved by adding toughening agents.At present,the commercial activated carbon electrode material on the market cannot meet the market demand for supercapacitors owing to the low energy density and low capacitance.Likewise,polyacrylonitrile-based nanofibers have rich micropores.Therefore,the development of carbon nanofibers with large specific surface area,wide pore size distribution,high electrochemical activity and high electrical conductivity is of great significance.The biomedical external material is with poor antibacterial,poor adsorption and easy to adhesion.Thus it is easy to cause secondary trauma and infection during the treatment.Thus,it is important to obtain a material with high adsorption performance,high poor antibacterial and stable structure.In this paper,graphene nanoribbons reinforced carbon nanofibers were prepared by electrospinning,and the mechanical performance of single carbon nanofiber was studied by in situ tensile method.In the graphene nanoribbons reinforced carbon nanofibers,the graphene nanoribbons act as a reinforcement while a nucleating agent to improve the surrounding polyacrylonitrile?PAN?matrix to form graphite carbon,thereby increasing the degree of graphitization of carbon nanofibers.The tensile strength of graphene nanoribbons reinforced carbon nanofibers with 2wt% graphene nanoribbons additions is 3.52 GPa while the elastic modulus is 70.04 GPa.And the carbon nanofibers with 2wt% graphene nanoribbons are with smallest specific surface area,smallest porosity and highest graphitization degree.In this paper,porous nitrogen doped carbon nanofiber nonwovens were prepared by electrospinning.The porous nitrogen doped carbon nanofibers have a large specific surface area,rich multi-stage pore structure,excellent electrical conductivity and high electrochemical activity.The soft templates and in situ doping are used to improve the pore size distribution and electrochemical activity.In the three-electrode system,6M KOH was the electrolyte,and the specific capacitance of PNCNFs-2-3 was 198 Fg^-1 at a current density of 1 A g^-1.The same material in the two-electrode system,after 5000 times cycles at 1 A g^-1,the capacitance retention rate is up to 104%.In this paper,porous graphene nanosheets/carbon nanofiber composites were prepared by coaxial electrospinning.The electrochemical properties of the composites and the static adsorption properties of the ovalbumin were systematically studied.The structure of the composite is stable.The porous graphene nanosheets/carbon nanofibers are not easy to adhesion and with good antibacterial activity,excellent adsorption performance as a material for wound healing.When the graphene nanosheets were added with 2wt%,the electrochemical performance of the graphene nanosheets / carbon nanofibers was the best.Under the three-electrode system,6M KOH was the electrolyte,and the specific capacitance is 142 F g^-1at 1 A g^-1.At the same time,the adsorption capacity of 1 mg m L-1 OVA solution was 6.5 mg g^-1 after 24 h static adsorption at 15 ?.