MXene-based flexible polymer composites as high dielectric constant materials

The MXenes have a hydrophilic surface, are biocompatible by nature, and have outstanding physiochemical properties, which makes them promising for sensors, fillers in polymer composites, electromagnetic shielding interfaces, Li-ion batteries, supercapacitors, field-effect transistors, transparent conductors, and energy-storage devices. MXenes are considered ideal conductive fillers and are used along with flexible polymers to enhance or modify their dielectric properties while maintaining high flexibility. This chapter reviews recent developments in flexible MXene-based polymer composites with higher dielectric constant (e) and low dielectric loss (tan d) values. The existence of these properties for flexible MXene-based polymer dielectrics is caused by (1) the outstanding metallic conductivity of MXenes, which leads to improved interfacial polarization because of the increased inequality in electric conductivity between MXenes and the polymer matrices and (2) nanocapacitor network formation caused by the good dispersion of MXene in many polymer matrices. The effect of MXenes on the dielectric properties of various polymer composites is addressed in this chapter.