Preparation Of Carbon Nanomaterials/Mxene Based Conductives And Electromagnetic Sheielding Applications

With the rapid development of science and technology,electromagnetic pollution has become a major concern in the modern world.In addition to satisfying high-efficiency electromagnetic shielding performance,electromagnetic shielding materials also need to meet the characteristics of low cost,light weight,flexibility,waterproof,durability,wearability,and absorption loss.Traditional polymer composite materials require high loadings of fillers to obtain high electrical conductivity and efficient electromagnetic shielding performance.However,this situation will lead to high cost,low processability,and mechanical properties of the product.In order to solve the above problems,this thesis has carried out relevant systematic research on the research ideas of developing new preparation methods or searching for conductive fillers with high conductivity to prepare low filler content,low cost,light weight,absorption-oriented electromagnetic shielding composite materials.The main research content and conclusions are as follows:First,self-assembly of graphene oxide(rGO)/single-wall carbon nanotubes(SWCNT)/dysprosium oxide(Dy₂O₃)through chemical reduction to prepare a three-dimensional network conductive framework,and then vacuum backfilling silicone rubber into the three-dimensional conductive framework to prepare rGO/SWCNT/Dy₂O₃/PDMS nanocomposite materials.Combine rGO with conductive SWCNT and magnetically permeable Dy₂O₃ nanomaterials to enhance the reflection and absorption loss of the material by increasing electrical loss,eddy current loss,interface polarization and magnetic loss,thereby significantly increasing the material's electromagnetic shielding performance.When the filler is 0.57 wt%and the thickness is 2 mm,the electrical conductivity and electromagnetic shielding performance of the PTGCDA composite material reach 0.12 S·cm^-1 and 20.9 dB,respectively.It provides a new preparation path for the preparation of lightweight,flexible,low-filler content and absorption-based high-efficiency electromagnetic shielding polymer composite materials.Second,this paper uses a new type of high-conductivity two-dimensional material-MXene.The MXene&SWCNT conductive paint is coated on the PET base film by the dipping method,and the PET/MXene&SWCNT/Si O₂/PDMS conductive composite material is prepared by the in-situ growth sol-gel method and the coating of PDMS with low surface energy.When the immersion reaches 15 times,the deposition density is0.0069 g/cm²,the coating thickness is 100?m,and the electromagnetic shielding value and contact angle can be as high as 48.4 dB and 153°,respectively.By conducting bending,abrasion and corrosion tests on the conductive self-cleaning fabric,the composite coating material still maintains high electromagnetic shielding performance(>30 dB)and stable water resistance(contact angle>125°),indicating that the material has excellent properties High-efficiency electromagnetic shielding composite fabric with environmental stability and self-cleaning performance.