The Study On Synthesis Of ZnO Composites And Its Application In Resin-reinforced And Wave Absorbing

Zinc oxide(ZnO)is an important inorganic functional material and has many excellent properties.It is widely used in ultraviolet absorption,photocatalysis,sensing,water purification,antibacterial and battery fields.In particular,one-dimensional ZnO nanomaterials have special application prospects due to their high aspect ratio and large specific surface area.The current traditional method of growing one-dimensional ZnO nanowires on a substrate is relatively single,and has the disadvantages of low concentration of reactants,long time consumption,and large amount of waste water,and cannot achieve mass production.In the first part of the research work of this paper,one-dimensional ZnO nanowires were grown on the surface of chopped carbon fiber(SCF)by alkali solution-conversion method to obtain modified carbon fiber(SCF-ZnO)and used it to reinforce epoxy resin(EP)composites material system.Since ZnO is a typical dielectric material,in the second part of the research work,it was combined with magnetic ZnFe2O4 nanoparticles to study the synergy between dielectric loss and magnetic loss in the system.In order to improve the microwave absorption capacity of ZnFe2O4@ZnO and prevent the self-aggregation of ZnFe2O4@ZnO microspheres,we used graphene oxide(GO)as the substrate to form the ZnFe2O4@ZnO@rGO ternary sandwich structure and further explored its microwave absorption mechanism.Through surface treatment of SCF,SCF-ZnO was prepared in batches based on the alkali solution-conversion method.Through comparative analysis,it was known that SCF-ZnO had a larger specific surface area(38.7 m2/g)compared to the SCF sample(specific surface area 5 m2/g).Thermal weightlessness analysis shows that the grafting rate of ZnO in SCF-ZnO was about 32 wt.%,and it had good thermal stability.SCF-ZnO was added into epoxy resin system,compared with pure epoxy resin system(EP),SCF and epoxy resin mixed system(EP+SCF),and blended system(EP+SCF/ZnO)formed by sequentially adding SCF and ZnO to epoxy resin,we explored the influence of SCF-ZnO on epoxy resin curing kinetics,thermodynamics and interface properties.The study found that SCF-ZnO could significantly reduce the activation energy of the curing reaction of the epoxy resin system.SCF-ZnO with a three-dimensional micro-nano structure was conducive to a good interface bonding of the epoxy resin matrix,and the bending strength of the composites was increased by 13.7%with the addition of 1%.In addition,SCF-ZnO also acted as a thermal bridge in the resin system,and the thermal conductivity of the composites material was increased by 51.9%with the addition of 1%addition.Based on the excellent dielectric loss performance of ZnO,ZnFe2O4@ZnO@rGO ternary microwave absorbing composites material was successfully synthesized through a stepwise controllable preparation method,and the electromagnetic parameters and microwave absorbing properties of the ternary microwave absorbing system were analyzed.By changing the amount of ZnO coating and the amount of graphene oxide(GO)added,the system achieved the best impedance matching.When the thickness was 2 mm,the optimal reflection loss of the ternary absorbing system reached-35.2 dB.At the same time,the absorbing mechanism of the system was systematically analyzed.The microwave absorbing performance of ZnFe2O4@ZnO@rGO was greatly enhanced due to the high dielectric loss performance of ZnO and the strong interface polarization of the ternary system.