A model for effective conductivity of polymer nanocomposites containing MXene nanosheets

This paper introduces a groundbreaking model to evaluate the conductivity of nanocomposites comprising MXene nanosheets. The model simulates the effective conductivity considering MXene dimensions, MXene volume fraction, interphase thickness, percolation threshold, contact distance, and tunneling resistance. The model's predictions align well with empirical conductivity results obtained various laboratory samples. The scrutiny of elements impacting effective conductivity is affirmed, given the assumption of contact resistance and the operation of the MXene/interphase network. Slender MXene nanosheets and expansive contacts lead to an elevated level of effective conductivity. Moreover, the effective conductivity shows a direct correlation with the MXene loading, while a higher percolation onset produces a poorer conductivity. Based on the model's outputs, an insulative nanocomposite is identified via the thinnest interphase (ti$$ {t}_i $$ < 1 nm), the thickest MXene (t > 4 nm), the smallest MXene volume fraction (phi f$$ {\phi}_f $$ < 0.01), and the lowest percentage of networked nanosheets (f$$ f $$ < 0.05). Contrariwise, the most remarkable conductivity as 25.6 S/m is attained by the thinnest MXene nanosheets (t = 1 nm). In addition, the narrowest tunnels (tunneling distance of 1 nm) yield the uppermost effective conductivity of 6.2 S/m in the system. Highlights This study proposes a model for conductivity of polymer MXene nanocomposites. MXene size, interphase depth, contact distance, and tunneling resistance are considered. The predictions agree with the experimental conductivity data of several samples. A higher conductivity is obtained by the bigger contact area and thicker interphase. The narrowest tunnels (1 nm) produce the uppermost effective conductivity of 6.2 S/m.