Preparation And Electromagnetic Shielding Performance Of Ti₃C₂T_x/Cu Composite For Aviation

With the rapid development of electronic technology,the problem of electromagnetic interference has become increasingly prominent,and they are a serious threat to flight safety.Modern aircraft systems integrate a number of electrical components and sensors are vulnerable to electromagnetic interference,which affects flight safety.Therefore,the research and development of high-efficiency electromagnetic shielding materials are critical to aircraft electronic components and sensors.Due to copper high conductivity,low cost,and easy preparation,it was the first choice for electromagnetic shielding materials.However,copper is easily corroded,and its application is limited.Ti₃C₂T_x material is a 2D material similar to graphene.It has high conductivity,easy film formation and excellent potential in the field of electromagnetic protection.In this thesis,a non-palladium activation system was used to prepare copper-plated glass fiber fabric by the electroless copper plating.The Ti₃C₂T_x-based and copper-plated glass fiber-based composite materials were prepared by vacuum filtration and coating process to obtain anti-oxidation and high-efficiency electromagnetic protection materials.The main research contents are as follows:(1)An electroless copper-plated glass fiber fabric was prepared using Cu SO₄-Na BH₄palladium-free activation system.The influence of electroless plating process parameters on the deposition amount,deposition rate,and conductivity of the coating was studied,and the optimal parameter was obtained:14g/L Cu SO₄,20g/L EDTA·2Na,12g/L C₂H₂O₃·H₂O,6 mg/L K₄Fe(CN)₆,p H=13,plating temperature 70?,plating time 30 min.Through SEM,XRD,XPS,and EDS analysis,the micromorphology and composition of copper-coated glass fiber fabric are analyzed under the optimal parameter.SEM showed that the copper on the surface of the fabric fiber was uniform and dense;XRD showed that the elemental copper had a face-centered cubic structure,and the copper grain size of the(111)crystal plane was 39.3 nm.By XPS and EDS analysis,the electroless plating the atomic percentage of copper was as high as 97.55%,and there was no oxide in the narrow spectrum of copper,indicating that the the plating layer was elemental copper;In 2-18 GHz,the electromagnetic shielding effectiveness of copper-plated glass fiber fabric can reach 79.45 dB.(2)The precursor Ti₃AlC₂ was etched by the in-situ hydrofluoric acid etching method,and the influence of the etching time on the microscopic morphology,composition,and phase composition was studied.SEM showed that the Ti₃C₂T_x,and the edge of the lamellae was intact after 36 h of etching.With the increase of the etching time,it caused the edge defect of the Ti₃C₂T_x layer;the XRD showed that the(002)characteristic diffraction peak of Ti₃C₂T_x appears at 2?=6.63°,the position of the(002)diffraction peak was 2?=6.63°,and it was located at2?=39.78°,and 2?=39.78°and 2?=41.75°which were the(104)and(105)characteristic diffraction peaks have the smallest intensity,indicating that there was less Ti₃AlC₂ remaining in the product;XPS showed that the Al element gradually disappears with the increase of the etching time.In the case of etching for 36 h,C-Ti-T_x binding energy strength was higher than that under other conditions.After analysis,it was concluded that Ti₃C₂T_x etched at 36 h was the best.The precursor Ti₃AlC₂ was etched with the optimal etching time,and the Ti₃C₂T_x film and MWPU composite film were prepared by the suction method.When the Ti₃C₂T_x film thickness was 14?m,the resistance was only 509.9 m?,and the shielding performance can reach 52.23dB.The shielding performance of the MWPU_3:1 composite film was 37.9 dB,and the EMI SE_Aof the MWPU composite film was dominant in electromagnetic shielding.(3)The Ti₃C₂T_x/Glass fiber fabric and Ti₃C₂T_x/Cu glass fiber fabric composite was prepared by vacuum filtration and coating,and their electromagnetic shielding performance was studied.The results showed that:Ti₃C₂T_x nanosheets are loaded on the surface of glass fiber fabric by suction filtration.SEM showed that Ti₃C₂T_x nanosheets cover the surface of the glass fiber fabric,and a dense layer of Ti₃C₂T_x nanosheets was loaded on the surface of the glass fiber fabric to give the glass fiber fabric conductivity;XPS showed that the surface of Ti₃C₂T_xcoated glass fiber fabric contains a large amount of-OH,-O,-F functional groups conducive to the absorption of electromagnetic waves.The electromagnetic shielding effectiveness was tested in 2-18 GHz.It was found that when the load was 2.55 mg/L,the electromagnetic shielding effectiveness reached 55.1 dB,which has excellent electromagnetic shielding effectiveness;Ti₃C₂T_x/Cu glass fiber fabric was prepared by coating.XRD shows that there was no copper oxide diffraction peak in the Ti₃C₂T_x/Cu glass fiber fabric composite,and the position of the(002)diffraction peak of Ti₃C₂T_x meets the requirements of standard cards;SEM showed that as the content of Ti₃C₂T_x increases,Ti₃C₂T_x nanosheets were staggered and formed.The3D conductive network of“Ti₃C₂T_x-Cu/glass fiber-Ti₃C₂T_x”improved conductivity.In 2-18GHz,when the content of Ti₃C₂T_x was 600 mg,the shielding performance of the composite material can reach 84.35dB.