Growth Of Vertical Graphene Sheets On Carbon Fibers And Studying Of Their Composites

At the beginning of the 21 st century,high-performance carbon fiber has been widely used in aerospace as a reinforcement due to its extremely high specific strength and modulus.As a reinforcement,carbon fiber reinforced resin-based composites have been used in the important structural parts,with the improvement of the mechanical properties of carbon fiber,how to make the carbon fiber reinforced resin matrix composite material better play the mechanical properties of carbon fiber has become an important research content;the surface modification of carbon fiber is through the surface of carbon fiber A method of changing the surface properties of carbon fibers by changing the surface properties of the carbon fibers.Research on improving the bonding strength with resin to improve the comprehensive mechanical properties is an important research direction for improving carbon fiber reinforced composites.Graphene nanosheet is a two-dimensional material with ultra-high modulus and specific strength.In this paper,the surface of carbon fiber is modified by thermal CVD method,and a certain thickness of three-dimensional graphene structure is grown on the surface of carbon fiber.Graphene nanosheets were grown on the surface;the matrix was made of epoxy resin,and the carbon fiber reinforced composite was prepared by vacuum bag forming method,and its mechanical properties were tested.The results show that after modification at 1100 °C for different time,a certain thickness of three-dimensional graphene nanosheets is grown on the surface of carbon fiber.The carbon fiber with vertical graphene sheet grown by thermal CVD was combined with resin,and the sample was prepared according to the national standard by vacuum bag forming method.A composite material with excellent mechanical properties was obtained.The test results showed that when the growth time was 10 h,the comprehensive The performance is the best,among which the tensile strength is increased by 22.0%,the tensile modulus is increased by 20.7%,the bending strength is increased by 21.7%,and the bending modulus is increased by 20.9%.After observing the cross section of the carbon fiber composite material,it was found that the bonding between the graphene nanosheet and the resin was not ideal.Therefore,based on the thermal CVD modification for 10 h,the carbon fiber was further electrically charged.Chemically modified,carbon fiber is used as anode,electrolyte solution is selected as 5% ammonium bicarbonate solution,modified under different current density conditions for different time,carbon fiber reinforced composite material is prepared by molding forming,and its mechanical properties are tested.The results show when the modification condition is 0.3 m A cm-2 for 5 min,its comprehensive mechanical properties are the best.Compared to untreated carbon fiber composites,its average tensile strength and average tensile modulus increased by 29.2% and 25.0%,respectively.Compared with graphene carbon fiber composites grown 10 h,the average tensile strength and average tensile modulus increased by 5.4% and 11.6%,respectively;compared with untreated carbon fiber composites,the average flexural strength and average flexural modulus were Increased by 8.1% and 26.6%.Compared with graphene carbon fiber composites grown 10 h,the average flexural modulus increased by 9.1%.