Surface-engineered electrospun PVA–CMC–SA/CuO–MXene fiber nanocomposites with enhanced thermal stability, antimicrobial activity and tunable dielectric performance

The development of multifunctional nanocomposite fibers that combine dielectric performance, thermal stability, and antimicrobial activity is of increasing importance for advanced flexible electronics and antimicrobial surface technologies. In this study, PVA-CMC-SA/5% CuO-based fiber nanocomposites were produced using the electrospinning method, and the effects of adding different ratios (5%, 7%, and 10%) of Ti3CNTₓ MXene to this structure on its thermal, dielectric, and surface properties were systematically investigated. The morphology of the obtained nanofibers was confirmed by SEM–EDX analysis, which showed that the CuO and MXene phases were homogeneously distributed within the fiber matrix. FTIR results revealed the formation of strong interfacial interactions between the polymer chains and the filler phases upon the addition of MXene. TGA–DSC analyses showed that thermal stability was significantly enhanced by MXene addition, with the glass transition temperature increasing from approximately 83 °C to 95 °C. Thermal decomposition kinetics were evaluated using the Kissinger method, and the activation energy was determined to increase from 104 to 159 kJ mol−1. Dielectric measurements revealed that the dielectric constant increased with the addition of MXene, while AC conductivity and dielectric losses exhibited frequency-dependent controlled behavior. In antimicrobial tests, increasing the MXene concentration from 0 to 10% quantitatively demonstrated that the inhibition zone diameters increased from approximately 10.7 mm to 14.7 mm for SA, from approximately 10.0 mm to 14.8 mm for EC, and from approximately 10.6 mm to 15.1 mm for CA, thus significantly improving the antibacterial performance of the composite. The results indicate that MXene-incorporated PVA-CMC-SA/CuO fiber nanocomposites offer tunable dielectric performance, improved thermal stability, and enhanced antimicrobial activity, making them promising candidates for functional electronics and energy-related applications. This work demonstrates a synergistic design strategy by integrating CuO nanoparticles and Ti₃CNTₓ MXene within an electrospun biopolymer fiber architecture, providing a multifunctional platform with improved dielectric, thermal, and antimicrobial properties.