Synergic effect of large MXene nanosheets and protective coatings on improved electroconductivity and wash durability of MXene/polymer-modified cotton fabric

E-textiles and their wearable analogues are finding applications in a myriad of sectors, ranging from sensors to health and sports applications. The development of a truly functional and reusable textile substrate presents a challenging task; its design encompasses the fabrication of optimal functional conductive particles, as well as devising strategies for their application that will ensure their functional properties (e.g. conductivity) are retained in an undiminished state for a foreseeable period. In the presented study, we tackled these two aspects in an interdependent way: i) The enhancement of the electrical conductivity of MXene-modified cotton fabric by increasing the lateral size of nanosheets during the Ti₃C₂T_X synthesis, and ii) The improvement of washing durability of MXenes on the fabric surface by selecting suitable protective coatings. The results of Scanning Electron Microscopy (SEM), X-ray powder Diffraction (XRD), Dynamic Light Scattering (DLS) and Atomic Force Microscopy (AFM) revealed the successful synthesis of large and stable MXene nanosheets with ultrathin flake-like nanostructures, high colloidal stability and delamination yields. Using multiple application procedures of dipping and drying, the MXene nanosheets formed extensive adhesion areas on the cotton fabric and overlapped the fibre pores, thus reducing the interfacial resistance between the sheets and improving the coating uniformity and, consequently, increasing electrical conductivity. Weaker adhesion and depletion of large nanosheets were further effectively prevented by protective polymer coatings. The MXene-coated/protected fabrics had sufficient electrical conductivity, even after 20 laundering cycles. Moreover, the surface hydrophobicity was negligibly reduced, preventing water accessibility and, thus, increasing the oxidation stability of the applied MXenes.