▎ 摘　　要

NOVELTY - Physicochemical doubly crosslinked two-dimensional transition metal carbide/nitride/carbonitride (MXene) composite films is claimed. The preparation of physicochemical doubly crosslinked MXene composite films comprises (i) mixing the MXene aqueous dispersion with water-soluble polymer aqueous dispersion, and dispersing evenly to obtain mixed aqueous dispersion, (ii) removing water in the mixed aqueous dispersion, and drying to obtain physically crosslinked MXene composite film sample and (iii) transferring film sample in the organic solvent containing cross-linking agent, carrying out chemical cross-linking reaction and drying to obtain final product, where the MXene forms conductive path in the MXene composite thin film. USE - Physicochemical doubly crosslinked two-dimensional transition metal carbide/nitride/carbonitride composite films is useful in electromagnetic shielding materials, electric heating materials, fireproof materials, waterproof materials, thermal conductive materials, sensing materials, electrode materials, biomedical materials, antibacterial materials and support material (claimed). ADVANTAGE - The MXene composite film: has excellent mechanical properties, oxidation resistance, hydrophobicity, waterproof and has excellent electrical conductivity and electromagnetic shielding function. The method: is simple, low cost and suitable for large-scale industrial production; consumes less production energy. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing physicochemical doubly crosslinked two-dimensional transition metal carbide/nitride/carbonitride composite.