▎ 摘　　要

NOVELTY - Method for preparing carbonitrides and nitrides (Mxene)-based flexible polyvinyl alcohol electromagnetic shielding composite film involves (i) using hydrofluoric acid to etch away the aluminum layer in the (MAX) phase, filtering, washing and drying to obtain layered Mxene, (ii) mixing the MXene and graphene through ball mill obtain MXene/graphene composite intercalated with MXene and graphene, (iii) dispersing the MXene/graphene composite and nano-particle magnetite in deionized water, ultrasonically treating the mixed solution, filtering, washing and drying to obtain magnetite-doped MXene/graphene ternary composite material, (iv) dispersing the magnetite-doped MXene/graphene ternary composite material and polyvinyl alcohol in water, and stirring the mixed solution until the filler is dispersed in the polyvinyl alcohol aqueous solution and (v) pouring the mixed solution obtained in the step (iv) into a mold and drying to obtain the product. USE - Method for preparing carbonitrides and nitrides (Mxene)-based flexible polyvinyl alcohol electromagnetic shielding composite film. ADVANTAGE - The method optimizes the impedance matching, is conducive to the attenuation of electromagnetic waves, and has excellent flexibility and compatibility. DETAILED DESCRIPTION - Method for preparing carbonitrides and nitrides (Mxene)-based flexible polyvinyl alcohol electromagnetic shielding composite film involves (i) using hydrofluoric acid to etch away the aluminum layer in the (MAX) phase, filtering, washing and drying to obtain layered Mxene, (ii) mixing the MXene and graphene obtained in the step (i) with a mass ratio of 5:1 through a ball mill at high speed to obtain an MXene/graphene composite intercalated with MXene and graphene, (iii) dispersing the MXene/graphene composite obtained in the step (ii) and nano-particle magnetite in deionized water in a mass ratio of 2:1, ultrasonically treating the mixed solution, filtering, washing and drying to obtain magnetite-doped MXene/graphene ternary composite material, (iv) dispersing the magnetite-doped MXene/graphene ternary composite material and polyvinyl alcohol obtained in the step (iii) in deionized water, and stirring the mixed solution until the filler is uniformly dispersed in the polyvinyl alcohol aqueous solution and (v) pouring the mixed solution obtained in the step (iv) into a mold and drying at 40-60 degrees C to obtain the product.