Dielectric properties of chitosan-based ZnO nanocomposites for high-frequency electronic devices

In this study, first the blend of poly(2-(3,5-dichloroanilino)-2-oxoethyl 2-methylprop-2-enoate) (PDCOEMA) synthetic polymer with chitosan (CS) was prepared by the hydrothermal method. Then, PDCOEMA-CS/ZnO nanocomposites were prepared by adding different concentrations ZnO nanoparticles with weight ratios (3%, 5% and 7% wt) produced by biosynthesis from Prunus spinosa extract. Impedance and dielectric characteristics of PDCOEMA-CS/ZnO nanocomposites were studied by using the impedance spectroscopy method. All measurements were carried out at various frequencies between 500 Hz and 1 MHz and at room temperature. For all nanocomposites, the dielectric constant (ε′), dielectric loss (ε″), and loss tangent (tanδ) were found to have a frequency-dependent character. As the frequency increases, the dielectric constant decreases while the alternating current (ac) conductivity increases. The ε′, ε″ and AC conductivity values are decreased when the ZnO doping concentration is increased. Additionally, the impedance (Z) decreases with increase in both frequency and doping concentration. The frequency response of electric, dielectric and impedance characteristics of PDCOEMA-CS/ZnO nanocomposites suggest that they are a potential material for high-frequency electronic devices such as MOS capacitors and MOSFET transistors.