The Polymer Society of Korea

Abstract

MXenes are promising conductive 2D materials, but their hydrophilic nature and poor compatibility with non-polar environments hinder their processing and coating applications. Here, we report a simple solution-phase approach for covalent surface modification of Ti₃C₂Tₓ MXene using di-alkylphosphonic acid molecules, which attach in a face-on configuration without the need for catalysts or linking agents. The functionalized MXenes become hydrophobic and show stable dispersibility in a wide range of organic solvents, while retaining high electrical conductivity. Importantly, the modified MXenes exhibit exceptional stability against oxidation, with no significant oxide formation observed even after 30 days. Owing to the strong ligand attachment, these MXenes can be uniformly coated onto diverse substrates—including Cu, Al foil, PET, Ni foam, and even Teflon—where pristine MXene typically fails to adhere. Films fabricated from the dispersions deliver comparable electromagnetic interference (EMI) shielding efficiency to pristine Ti₃C₂Tₓ, but at reduced thicknesses. This facile and scalable modification strategy demonstrates a powerful route to produce long-term stable, processable, and conductive MXenes for advanced EMI shielding, flexible coatings, and printable electronic applications.